It's not that long ago. GIF certainly predates it. I think ZIP does as well, and probably EPS, just to name a few for scale.
None of these does exactly what PSD does of course, so it's impossible to compare them.
A better example is perhaps TeX, which predates it by far, has been extended a lot during the years, and can still render both original documents as well as modern ones.
GIF, EPS, and ZIP do the same thing as they did decades ago. PSD does radically different things. Things that were, as I said, completely unpredictable at the time the format was started.
None of these does exactly what PSD does of course, so it's impossible to compare them.
A better example is perhaps TeX, which predates it by far, has been extended a lot during the years, and can still render both original documents as well as modern ones.