A few comments...
CD-i failed for lots of reasons, one of which was the fact that the gamepads utterly sucked, and the systems all used proprietary connectors so you couldn't just go out and buy one you liked better. If Phillips and Electronic Arts had a gram of common sense, they would have made their controllers compatible with the Sega Genesis.
Another problem with CD-i: its main competition was the Commodore CDTV (based on the Amiga), which was doubly-problematic. The CDTV wasn't just overpriced and lame (compared to a real A500)... it also blew the CD-i away graphically, sonically, and in every other meaningful way because Phillips intentionally cheezed out on the hardware specs and left everything dependent upon a tiny framebuffer limping along with a slow drive that had even slower seek times and no inherent music-synth capabilities to speak of. Apparently, they REALLY DID think "Dragon's Lair" was going to be their "killer app." It's as though the creators of Dragon's Lair (groundbreaking and cool in its day or two of glory, but fading quickly for obvious reasons) were locked in a dungeon the day after it came out, and kept busy for 6 years developing a "multimedia" system based on the same technology, and never learned a thing from its very real shortcomings.
Onward to VCD...
If you define "failure" as "lack of prerecorded media and mass market sales", yes, VCD and its children were complete failures in the US. HOWEVER, you can't forget that between ~1999 and 2002, they were the de-facto standard for home-burned discs (both ripped from DVD and home movies). By the same standard, Metal cassette tapes with Dolby C were a complete market failure, yet EVERYONE I knew used them for compilations from CDs from ~1986 until ~1997. Don't forget that mp3 was fairly widespread and ubiquitous for YEARS before you could actually purchase mp3 songs of major artists, or even buy a dedicated player to listen to them.
Backtracking a bit to VHS vs Beta...
The rental-availability gulf was nowhere as bad as some people make it out to be. Not all video stores carried Beta... but the ones that did generally had everything in both. Even in complete backwaters like Naples, Florida circa 1984. There were more VHS tapes, but they were almost all due to having multiple copies of new releases in VHS, vs a single copy in Beta. I can't think of a single movie I wanted to rent that was genuinely not available in Beta, but was available in VHS (confession: I was under 15 and my parents had to cosign everything, which pretty much eliminated anything "R" rated from consideration and might skew the ratio a bit).
Also, even way back then, EVERYONE knew VHS tape-handling sucked compared to Beta's. I might have gotten the name wrong a few posts back, but it was precisely the arrival of Beta-like tape handling (specifically, the ability to INSTANTLY launch into fast forward or rewind while playing) n a VHS VCR that got me to switch sometime around 1987.
As for computers, you left out the best possible example of a technically superior platform gradually falling off the earth: the Amiga. When it came out, it blew away every other computer. It was the
unquestionably elite computer to own. It wasn't just a computer... it was a religion and way of life. If you think Linux users are bad, watch an old videotape of a late-80s Amiga Users Group meeting. When we used to have a table to recruit members on campus (showing off eurodemos, games, and a member's genlock), even the religious cults steered clear because we scared them too much
The problem was, it was too tightly bound to its low-end hardware (read: A500 w/512k and no hard drive), and couldn't evolve further without breaking just about every piece of software in existence (as a former A3000 owner, I can vouch that its purchase instantly broke about 70% of my software collection, especially anything and everything resembling a European videogame... even stuff that worked with my '030 card broke). Ultimately, Commodore went into financial meltdown (partly their own fault), and the Amiga Technorati grudgingly bought uber-high end PCs...
...Then quickly realized that you could eliminate every single PC owner with less than a 486DX-33, Tseng ET4000 videocard, 8 megs of ram, and a Gravis Ultrasound and still
have a potential market twice as big as the Amiga market ever was at its peak. And so arrived Comanche: Maximum Overkill -- a game whose stiff hardware requirements utterly freaked out the mainstream American videogame industry and set in motion the changes that now make hardcore Gamers the most coveted market for the fastest and most expensive CPUs available. DOS Extenders like DOS4GW didn't magically appear out of nowhere... they were written by former Amiga programmers who utterly refused
to deal with memory segmentation and 16-bit realmode crap when the 386SX and beyond all had perfectly good orthogonal assembly language and flat memory maps as long as you were willing to cast aside tradition and backwards compatibility with old PCs