CDs (as in compact discs). First released for music, they turned out to be a very interim technology. Music CDs didn’t provide even as good sound quality as the LPs they aspired to replaced, and didn’t really solve the problem of skipping or media lifetime that they were so relentlessly hyped at the beginning to solve. Really, the whole offered very dubious value. For a while CDs etc. were also used as computer media – and suffered from almost all the same problems as their magnetic counterparts. They briefly offered higher data density, but were quickly annihilated by solid-state media (Flash drives), which even when media CDs were first released, were clearly the future of storage. I don’t think anyone shed a tear when the CD became for all intents and purposes obsolete.
Fluorescent lights are another one pointed out by another poster, which again proved to be an interim technology, and a particularly poor one at that with harsh lighting combined with annoying flicker. EVERYBODY hated fluorescents. Ironically, a lot of houses were wired with fittings that only accepted fluorescent bulbs, which meant either a lot of refitting or weird adapters when the obvious answer – LED lights – started appearing. Although it must be admitted, that unlike CDs, which were predictably obsolescent even at release, there was a LONG time when it was far from clear that anything like white LEDs were possible.
Plasma TVs are yet another. They didn’t provide better picture quality than CRTs, were in any case rapidly displaced by LCDs, which in turn are quickly becoming replaced by OLEDs. Like the CD case, it was very clear plasma TVs were a purely interim technology.
Looking further back there are plenty of others: Zeppelins, Clipper ships, corbelled arches. All interim technologies that created almost as many problems as they solved and were replaced by far better and more permanent options later.