I think it’s a pretty common choice when you want compression in a new format or protocol. It works better for compressing chunks of your data rather than large files where you want to maintain some kind of index or random access. Similarly, if you have many chunks then you can parallelise decompression (I’m not sure any kind of parallelism support should have been built in to the zstd format, though it is useful for command line uses).

A big problem for some people is that Java support is hard as it isn’t portable so eg making a Java web server compress its responses with are isn’t so easy.