Another use case: It could be useful for one software deployed in more than one server and if admins want to enable/disable features specifically for every server.
Similarly, you can leverage this to wire traffic to DB replicas for instance. This if you need to handle traffic to DBs under specific scenarios (DB problems, burst of traffic, bugs, etc).
So basically a purely technical feature flag (paying attention to authorization as always)
I am not sure what your tech stack implies (I know nothing about it) but I think you don't really need feature flags, just better project planning and structure