Yes, QA should exist, and should be managed by Operations.

I've been places where devs have no idea what the product-as a whole-does. They just work on the feature of the sprint and throw the code over the wall. Their testing consists of if: it compiled==it passed. They have no idea how to even start actually testing if it's not on the happy path.

I been in places where the code accomplished the spec, but in the most lazy way possible so it appeared to work but was useless outside of what the tests looked for.

I knew one QA guy that was amazing but was so overloaded because management kept hiring "cheap" QA that were actively making his life worse.

I'm a tech writer right now at a tech company and a dev just sent over an LLM generated "doc" that's referring to things that don't exist.

Neither management nor dev has learned anything from Therac-25. QA is hard.