I used fish for a long time, but lost patience with the incompatibility with other shells. It’s nice to be able to just paste and run someone else’s command, and I eventually tired of having to rewrite every command to use fish syntax. For example, replacing FOO= with set - x … The reverse is even worse—if I need to send someone a command to run, I have to rewrite it in a syntax that’s likely to work when they run it. It only takes a few seconds each time but I grew weary of it.