That largely aligns with my view. I think in a large enough codebase (roughly the size QA becomes necessary/relevant) it becomes impossible/infeasible to guarantee correctness. I think the line "clever test suites" highlights the distinction.

In my mind, tests are everyone's responsibility, but the goal differs. A regular developer adds features and should be writing tests to prove their code functions as intended. QA does not add features, so their goal is finding holes in code added by others.

It's the adversarial relationship mentioned by a parent:

> Have [QA] build tests to break the code. Don't give [QA] the job of making a test suite that passes.