glibc breaks regularly, as does mesa occasionally, so it would realistically be required if you wanted win32-style 20+ years of backwards compatibility.
And there is a lot of more obscure examples: fontconfig e.g. at some point changed their config file format in a not backwards compatible way, and now some Steam games crash on startup because the developers earlier vendored it to get around its ABI breaking repeatedly.
And that sort of software doesn't really obsolete. Steam and GoG allow games to have a 10+ years long tail of slow but steady sales that don't really justify constant maintenance releases but still both let people enjoy good games (those don't really obsolete), and serve as advertisement for the developers' newer games.
