The claim that zstd is "better and faster", without additional qualifications, is false and misleading.

Indeed for many simple test cases zstd is both better and faster.

Despite that, it is possible to find input files for which zstd is either worse or slower than gzip, for any zstd options.

I have tested zstd a lot, but eventually I have chosen to use lrzip+gzip for certain very large files (tens of GB file size) with which I am working, because zstd was always either worse or slower. (For those files, at the same compression ratio and on a 6-year old PC, lrzip+gzip has a compression speed always greater than 100 MB/s, while zstd only of 30 to 40 MB/s.)

There are also other applications, where I do use zstd, but no compressing program is better than all the others in ALL applications.