The problem of handoffs makes this work far from cheap.

And tests are not dumb work. TDD uses them to establish clarity, helping people understand what they will deliver rather than running chaotic experiments.

Highly paid people should be able to figure out how to optimize and make code easy to change, rather than ignoring technical debt and making others pay for it.

QA is just postponing fixing the real problem - hard to change the code.

The best QA people I've worked with were effective before, during, and after implementation - they worked hand in hand with me both to shape features testably, work with me on the implementation for the harness for additional testing they wanted to do beyond what was useful for development, and followed up with assistance for finding and fixing bugs and using regression tests to prevent the category of error from happening again.

At the very least I want someone in QA doing end-to-end testing using e.g. a browser or a UI framework driver for non-web software, but there's so much more they do than that. In the same way I respect the work of frontend, backend, infrastructure, and security engineers, I think quality engineering is its own specialized field. I think we're all poorer for the fact that it's viewed as a dumping ground or "lesser"