Betamax lost the consumer wars but it was a stunning success in the commercial world. Unsurprisingly the better technology was recognized by professionals.
All those shoulder mounted television cameras? Betacam, the most widely used tape format for Electronic News Gatering (ENG).
Betacam dethroned the reigning king, U-Matic. VHS never carved out a strong foothold in the commercial space.
However, videotape was never really future tech for consumers.
"Future tech that didn't make it" are really entire concepts that failed.
One videotape format eventually won over Joe Consumer and it had a long and popular life in the consumer marketspace.
Same with Blu-ray vs. HD-DVD. HD-DVD isn't future tech that failed. The tech was successful (high-density optical media based on blue lasers) it's just that one implementation was less popular and was eventually discontinued.
SACD is a better example of future tech that failed. It and any competitors it may have had all failed. Even optical media players sold five years ago didn't even support SACD. But even then, something better stepped into its place. Today Blu-ray Audio discs offers some great sounding music 96kHz/24-bit all playable on a typical standalone Blu-ray player.