It's sort of a defining feature of the tech industry to always keep a handful super-hyped "revolutionary" technologies around that in the end never amount to revolutionize anything all that much.
Some examples:
- Interactive videodiscs
- Visual programming
- Virtual reality
- Pen computing
- Java applets
- Artificial intelligence
- VRML
- Blockchain
- OpenDoc
- Speech recognition
- VLIW architecture
Some are outright failures, some found niche applications.
Reply with more examples!