So many websites from 10 or 20 years ago are unusable now -- if they're even still available. That seems to me a bit of a tragedy. It's sad to just write off that entire slice of human history.
Funnily enough, it's the sites that were quick to adopt the hot new HTML and CSS features from 10 years ago, but then were unable to keep updating indefinitely, that were the worst hit. Really old sites using basic HTML and CSS mostly work OK.