The time period is asinine; 20 years is forever in most industries
In tech, yes, 20 years is a lot, but that's more of an exception.
And imho, it's slowing down: A 20 years old computer, like an Athlon 64, today, could probably run most of the usual basic workloads (mail, text, word processing, browsing) with up to date software. It would be slow, but it would work. An 1983 years old computer in 2003 was just obsolete and completely unfit to run any of the usual 2003 software.