One of our development groups is using a git repository manager from another vendor that allows us to delegate authority for access control, hooks/triggers, etc. for the set of repositories within a defined project.
From a overall SCM administrator's perspective, this one capability makes my job much easier. I no longer have to be as tightly integrated into each development groups workflow and processes.
While we could achieve some of the same benefits by spinning up separate perforce instances for each projects, we would lose the benefits of a single infrastructure (single centralized backups, worldwide replicas, etc.) at the same time.
There is already an open idea for delegated user/group management (Grant User and Group management to Operator account), but this suggestion is to go even further and allow delegated permissions and trigger settings (perhaps on a depot level).