As audio formats have risen and fallen from favor, there have always been segments of audiophiles there to fly the flag of their favorite format, and to shun the supposed failures of those they oppose.
Sliders on TL Audio VTC (1), Metway Studios by Jeremy Keith is licensed under CC BY 2.0
Truly, each format has its respective merits and caveats. The choice of one format over another is mostly preferential based upon one's circumstances. The favor for portable digital formats is most often made for convenience, and those listening from their mobile devices while commuting are seldom concerned about the quality of the device's internal DAC (digital to analog conversion) or of the lossy compression which leads other audiophiles to write their congresspersons in fits of anger and audio activism. Pragmatically speaking, (respectable fringe circumstances aside), portable listening environments, given the significant white noise and distraction of passersby, reduce the need for performative excellence in audio signal reproduction, as much of the nuanced perfections of a given recording are lost in the chaotic shuffle of human transport.
CDs are a sufficient marriage of quality and convenience for many listeners. They lend an optimum sound quality for properly-mastered and mixed recordings, are a widely-supported format, and can readily be converted to lossless EAC (exact audio copy) or lossy MP3 for added portability. They suffer the usual limitations of physical media - entropic decay, limited capacity forcing albums to restrict run-time, and jewel case hinges which are frustratingly breakable. Title availability is often limited to commercially-viable recordings, which may or may not be an issue depending on your genres of interest.
There appears to be a curious consensus that the many of the earliest discs (roughly 1981-1989) are inferior in their sound quality. Listeners often complain that these discs sound "tinny", "bright", or "thin." However, a quick search reveals intriguing opposing views, suggesting that the supposed poor sound quality of early discs may be a myth after all. It is important not to mistake earlier, quietly-mastered CDs as inferior. Podunk from the quartertothree forum offers the following:
"...mastering techniques have changed a lot since the 80's and early 90's. The most significant change is the tendency of mastering engineers to apply a lot of compression or hard limiting to final mix, which greatly decreases the dynamic range of a recording but makes it sound really loud and punchy. Recordings from even the early 90's sound much quieter than modern recordings because of this practice. The advantage to that kind of aggressive compression is that our ears initially percieve loud recordings as sounding generally better, bassier, punchier, etc. Also, a loud recording will reveal fewer of the weaknesses of a cheap cd player/receiver/etc, because you don't have to turn it up until you start to hear the background noise from your system. The disadvantage to that sort of mastering is that listening to a recording with very little dynamic range is fatiguing, but at first blush, that is probably the #1 reason that a new CD would sound better than an old one: at the same volume level, a new one will sound much louder and punchier."
Ethan Winer of Music Player Network agrees, stating that some early CDs were poor due to improper mastering, but that these are the exception rather than the norm. During the early days of CDs, some engineers directly used "...master tapes meant for vinyl records, with treble added to counter the known high-frequency loss of LPs." Alan Cross published an article on 10 of the Worst-Sounding CDs of All Time, which includes the terribly hissy, My Aim is True by Elvis Costello. But you'll find that each of the early albums on his list is an example of shoddy production work at the hands of the studio and not limitations of the format or its technology.
Another factor to consider is that early 80's music itself is characteristically bright and tinny, further contributing to the perceived poor sound quality in comparison to post-loudness-war era recordings. Personally, I delight in the sound of early synth-pop albums and their characteristic brightness, and if I elect I can simply adjust the equalization to taste - far better than having to deal with the over-compressed dialed-up-to-eleven victims of the loudness war!
Cassettes rival other formats in two primary ways - their portability, and more importantly, the participatory factor of the mixtape - a cultural phenomenon which permitted the listener to contextualize and identify with their music and to share it with others. Music became far more socially interactive with the birth of the cassette. This also created an environment for DIY home recorded genres like punk and was critical to the development of independent music. This, of course, continued with the democratization of CD burning technologies some years later.
Even as a devout record collector, it is important to state that the format's allure is largely fetishist and a placebo effect. Young listeners born in the era of digital music enjoy discovering the retro format as it provides a tactile and real-time listening experience, and it gives a (literally) substantial value to music they would otherwise perceive as common, elemental, and as plentiful as air and water. Gatefold artwork is often breathtaking and elegant. Sound quality is dependent on a combination of the source audio, the mastering process, the condition of the disc, and the playback equipment utilized. To various degrees of impact, the selection of tables, tonearms, cartridges, interconnects, pre-amps, power amps, and speakers each play a role in the resulting sound. However, the nostalgic "warmth" described by many vinyl lovers is simply a distortive property of the medium - a characteristic of playback altering the true audio signal of the artist, producer, and engineer, just as the crackles and pops of a well-worn and well-loved LP add a vitality and character to the music representing its history as a badge of honor, like the scratches and scars on the face of a dedicated soldier.
One important additional characteristic of the vinyl format is that there are tens of thousands of titles issued on LP which will never be made commercially available in a digital format. Thankfully, listeners have risen to this challenge and through online music journals and sites like Archive.org, have come together to digitize worlds of music which would never see the light of day without their efforts. In fact, the very same has been happening in the cassette community, both in the audio and video realms.
MP3 offers the convenience of compression and shareability, and was the first widely successful, non-physical format. They offered the same flexibility as mix tapes with the added bonus of storage of tens of thousands of tracks on a small drive, plus the post-scarcity economic quality of being infinitely replicable at no cost to the user. There was a brief "dark age" of digital music in the early days of Napster with no bitrate standard and file exchange systems based on tracks instead of albums or discographic archives of artists or record labels. This quickly passed as technology progressed to appease more discerning listeners who demanded standardization of formatting and v0 compression.
Still, some listeners prefer archival quality audio and have no use for single-track exchange networks. This is where archival lossless digital audio factors in. Private FLAC-based trackers offer an incredible value to users with meticulously-structured and uniformly-extracted FLAC+.CUE + .log packages for all available libraries. Complete discographic archives are instantly accessible, whether showcasing a single artist or composer, or an entire record label or musical theme. Finally, a format had arrived which offered a truly contextual listening experience--complete with catalog numbers and uniform metadata for well-organized archival libraries, and with enhanced accessibility.
Best of all, these communities offer vastly larger libraries of content than commercial channels which focus only on licensed recordings. FLAC communities offer artist demos, developmental works in progress, live performances (whether sourced from soundboard or field), and an array of other non-commercial recordings not available to the public at any price.
Streaming services have grown to be incredibly popular as of late given their convenience and accessibility, though more discerning listeners collectively deride the technology as being painfully inadequate for their own listening needs. The disdain is three-fold. Firstly, the services are limited to commercial recordings for which they can secure licensing, which instantly reduces the available catalog to a tiny fraction of the world of recorded music. Secondly, inferior lossy compression rates have turned many off from using these services. Finally, and perhaps most importantly, there is the principle behind the service's greatest flaw - namely that listeners never own any of the music they hear on these services. There have already been instances of titles being remotely deleted from user libraries, hinting at the dangerous potential for media censorship at the hands of the content distributor. The EFF and other open culture organizations caution consumers that collectively relinquishing ownership of creative works is incredibly dangerous for a society. Fortunately, a percentage of listeners still hold fast to the concept of personal libraries and elect to retain the public's control of our art.
What is to come of these formats in the years ahead? Vinyl will retain an audience of collectors who desire a tangible connection to their music and a lust for magnificent artwork. CDs will experience a nostalgic, retro-renaissance as all things do approximately 20 years after their era. Cassette culture is already on the rise, albeit a niche, (though the same was said about vinyl just a few years ago). Each format excels in areas which appeal to their respective fan base. It will be interesting to see what transpires with non-physical, digital audio. As storage cost continues to plummet, we've reached a threshold where compression and storage are non-issues. And as accessibility (in both legal and non-legal forms) continues to become refined and democratized, we may approach a day where every user can possess a personal copy of the Library of Congress, readily accessible for their perusal, research, and literacy. As open culture explains, this has the potential to usher in a new age of artistic enlightenment.
I hope I'm around to see that day.