In a tool I wrote zstd is used for essentially all data exchange (inside an SSH connection; SSH itself does compression, but that doesn't support zstd [yet], and connection-level compression is not necessarily a good idea in the first place). It's pretty phenomenal. For stuff like backend JSON API calls I regularly see compression ratios of around 25-30x (for 20-50 MB of JSON) and for bulk data transfers it often exceeds line-rate by quite a bit.

gzip in comparison delivered very-nice but only half as good ratios of around 15x. For the "bulk transfer" case gzip went fairly slowly, it couldn't nearly reach gigabit rates - it still transferred less data, but it took significantly longer than uncompressed and still longer than compressed.

gzip slows down a lot on incompressible data (not as bad as LZMA though), so it's not a good choice as an "always-on" compression. zstd on the other hand handles incompressible data very well. Unless the I/O is quite a bit faster than 100 MB/s, using zstd will very likely only improve things.