I tried directly coding on the Mac when I first got it, but quickly gave up on that. (I hate Rider, which seems to put me in minority as far as most .Net devs go.)
I haven't really tried to write serious C# code on macOS, but I did write some CLI tools, which was not bad. VSCode debugging works great too.
Obviously .NET is not supported as well as it should anywhere except Windows, but it seems to be getting better.
I could get away with doing dev directly on the Mac if I was _only_ working in .Net Core on our newer applications and if I was willing to use Rider. Neither of which are true.