Zillions of people. Usually it gets called steampunk (18xx) or dieselpunk (193x-194x). 195x-6x futurism usually ends up going very Googie. And we’re starting to see 70s/80s retrofuturism, mostly I’d say the word associated with that is vaporwave.

More art than actual tech, and most of the tech is one-off hand-built stuff.

Cassette Futurism for the '80s. https://tvtropes.org/pmwiki/pmwiki.php/Main/CassetteFuturism

Vaporwave, despite using a lot of 80s samples, is generally more associated with the 90s. Vaporwave is all about the simultaneous apex and decline of mall culture, consumer excess in optimism of the post-Cold War, and early WWW aesthetic.

70s/80s would be Cassette Futurism and Sythwave.

Would cyberpunk count as 90s retrofuturism? Or have we decided it hits too close to home for present times?

Nah cyberpunk is it's own thing and the aesthetic way predates the 90s.

Cyberdecks[0] come to mind. There seems to be quite an active modding scene; I remember seeing a few Pi-based ones recently.

[0] https://www.cyberdeck.cafe/