I had the same issue, I have tried all this command multiple times restarting everything many times.
The issue was that key repetition was not enabled on my mac (Even if it was enabled on settings);
To try it just go in any page and try to press a key and see if it repeats multiple times.
If not that's the issue!!
To enable it you first have to run this command:
defaults write -g ApplePressAndHoldEnabled -bool false
Now you have to run this for normal VScode:
defaults write com.microsoft.VSCode ApplePressAndHoldEnabled -bool false
Or this for VSCode Insiders:
defaults write com.microsoft.VSCodeInsiders ApplePressAndHoldEnabled -bool false
Now you have to close VSCode totally (not using command Q) right click icon quit for me. Then reopen it and should work :)