I've never worked in this way (when I've been part of the org), is it that common? What are the benefits of making everyone fork repos vs branching off the original repo?
It's common in general open source projects where you might want to send a patch for something that you don't have commit priveleges too, but I've never seen that used in enterprises as they have central auth / groups with the users required to work on the code.
I worked at a large gaming company and that was definitely the collaboration model.
Before per-branch controls, the only way to disable write access (while maintaining read access, pull-request privs, etc) to a repository's blessed branches was forks.
