It's not just the code, we'd want everyone on the team to use the appropriate toolsets including debugging and error checking support. They can set it up in Vim and Emacs if they want but it saves time for the team as a whole if we all use a standardized set of tools.
It takes weeks (at least) using emacs/vim until text editing/movement starts to pay off. There's no learning curve for `M-x package-install`, but if there is some variable that needs to be customized, like the path to an executable or something, that's a whole rabbit hole to go down, and at some point you need to learn lisp or you'll waste a lot of time being confused by errors.
During the only programming course I took in college, one in which emacs was required, I spent as much time learning emacs as anything else (it was also the most valuable thing I learned so I'm grateful in the long run).
The only time I ever had to use vscode working with other programmers was for pair programming, using the vscode sharing thing. Apart for that, not being able to use emacs would be a deal breaker - using other editors is like wading through quicksand for me.