Being CGo-free is very desirable when you can't/don't want/don't bother to link C library deps for some reason. On example when you don't want to do that is cross-compiling for another architecture and not really being able to control what runtime libraries are installed on the target.

So, it simplifies build pipelines, at the cost of being a bit slower in the runtime.

This is also nice to read about the topic: https://dave.cheney.net/2016/01/18/cgo-is-not-go