When you open a file for writing in perforce, it checks whether anyone else is working on the same file, and tells you who, if someone is.
This is a fine feature. It warns you if there was a
misunderstanding and someone else is already doing what you're about
to start doing, and it warns you if someone else has forgotten to
commit a change. The price for that is that the perforce server has to
know who has the file open for writing, and that when you see that
x is also editing y, you have to talk to
x about whether your work conflicts.
Git has nothing like a perforce server, so no place to check for such approaching conflicts.