Hobbyist collectors of typewriters (I know because my father is one) and cars (one of my friends is one) all have to learn how to maintain and service their own stuff because businesses that did that for them have all but disappeared. It’s considered part and parcel of the hobby.
It’d be nuts to expect it to be any different for computer collectors. Compile your own kernels, diagnose your own problems, fix your own shit. That’s what you do for a hobby. :P
If you’re running something that old, then it is by choice anyway, hardware gets more expensive after a certain age, and you definitely won’t be getting a (functional) 90s computer for cheap.