Permissions? ie different teams with different push/pull rights for different repositories. We have that where I work; for most projects it seems like needless

Permissions? ie different teams with different push/pull rights for different repositories. We have that where I work; for most projects it seems like needless complexity, but some things are more closely controlled; payment handling, ops (where a change could bring down the whole org not just an app), etc. There's also the issue of contractors being brought in, generally they see a restricted subset of the codebase.