Yeah, for a lot of companies, this is way overkill. Thats fine, don't use it! In the places I have seen use it when it is actually needed, the controller makes a lot of work for teams disappear. It exists, because thats how K8S itself works? - how it translates from a deployment -> replica set -> pod -> container.

Abstractions are useful to stop 100000s lines of boiler plate code. Same reason we have terraform providers, Ansible modules, and well, the same concepts in programming ...