I agree that vintage/ancient computers aren't really usable as "daily drivers". But they sure as hell are fun to mess around with....
I've always been a bit of a vintage freak. I love taking really old computer hardware, maxing it out to the absolute limit of its abilities & seeing just what it might have been capable of, back in the day. But that IS for "fun". It's a hobby.....MY "hobby".
Puppy helps enormously with this kind of endeavour. Our community archivist, Ally - from Lincolnshire, here in the UK - has a paid account at archive.org, and has archived every piece of Puppy software ever created.......along with every Puppy ever built, going all the way back to beta-0.1, from mid-2002. The early Pups were ultra-lightweight, with extremely modest hardware requirements, and would run on almost anything back then.
My current HP Pavilion desktop rig is the first truly "modern" computer I've had. It's a real eye-opener, comparing it to what came before.....but I shall never be a true geek, that absolutely MUST run the very newest of everything, the instant it appears. Hell, I didn't adopt CDs until 2001; nearly 20 years after they first appeared.....and by then, they were all but obsolete, already being dropped in favour of solid-state MP3 players.
I like to let tech "prove" itself before investing..!
Mike.