For example wine-staging (ran by Wine developers themselves) hosts patches for Wine project and they revise / rebase them with each Wine version, which is often not a trivial task. I don't see how you can avoid that really. But Wine staging itself is a git repository that holds patches (and their history) if that helps, which indeed can stay there for years.

Same happens with patches that Debian applies on top of fixed versions of packages. They are stored in Debian's Salsa git.