I agree as far as the feature set is concerned, but software unfortunately doesn't exist in a vacuum.

A vulnerability could be discovered that needs a fix.

The operating system could change in such a way that eventually leads to the software not functioning on later versions.

The encryption algorithms supported by the server could be updated, rendering the client unable to connect.

It might be a really long time before any of that happens, but without a maintainer, that could be the end.