gzip has the advantage of being ubiquitous. It's pretty much guaranteed to be available on every modern Unix-alike. And is good enough for most purposes.
Zstd is getting there but I personally don't bother with it on a daily basis except in situations where both performance and compression ratio are important, like build artifact pipelines or large archives.
You're reading old comp-sci usenet discussions from 1993 and you come across this statement: "pkzip/lzh/arc/zoo have the advantage of being ubiquitous. We should not encourage the use of gzip". You chortle.
Zstd is getting there but I personally don't bother with it on a daily basis except in situations where both performance and compression ratio are important, like build artifact pipelines or large archives.