For seniors, sure that makes sense, use whatever editor you want, but for onboarding juniors, we definitely have a recommended toolset just so we can make sure there aren't incompatibilities and that their productivity is still high, ie having a debugger when needed, using code completion, error checking, linting tools etc.

My point is you could configure all this stuff in Vim or Emacs but it's not as straightforward plus it wastes time when onboarding. We'd rather have an IDE like experience.