I watched Casey's earlier streams. The only thing he likes VS for is the debugger. He would say he's looked and hasn't found anything better, but expressed a strong desire to find something else.

Since he started streaming he has moved (from emacs?) to I think http://4coder.net/, which seems to have spawned from his audience. Similarly, a few debuggers have, too. https://remedybg.handmade.network/ https://lysa.handmade.network/ but I think he still uses VS' debugger.