An operation in git makes you stat() each file in the current repo -- so things like check-ins and local operations would be done 100% in the current repo.

Any time you were pulling the entire repo tree, it could be slow, yes. But assuming people are only working in one or a small number of repos at once, you can imagine a workflow that didn't involve nearly so many operations on the entire tree.

Ah, I see. Yes, that might make some of those operations better. Other operations that are common in our workflow might still need to look through the whole super-repo - for example getting a list of all changes (staged or unstaged) in the repo and generating a code review based on that.

(I almost habitually run "git status" whenever I've task switched away from code for even a few seconds to make sure I know exactly what I've done, which would have to look over the whole super-repo as well.)

Thankfully we're a while away from the times based on the synthetic test - it's not something I notice at all, but I probably write less code than most engineers here.