I wrote "or any other binaries, really". It's just that

(a) go compiles static binaries which makes UPX especially effective, unlike e.g. common C and C++ projects with their hundreds of .so/.dlls ; Delphi/FPC and Nim or the other two ecosystems that share this trait, but neither is as common as go.

(b) it's not good for non-static binaries, that is C#, Java, Python have no benefit from this.

(c) At the time I posted it, there were already 3 or 4 posts extolling the virtues of compressing Go executables.

Many go programmers statically compile their code, which should make the paging problem worse.

If you look at other responses large number of them actually mentions that UPX works really with go and docker, I believe it was response to that.