I think the thing missing from a lot of these conversations is what problem domain you're working in. The more "technical" your problem domain is the more valua

I think the thing missing from a lot of these conversations is what problem domain you're working in. The more "technical" your problem domain is the more valuable automated testing will be over manual. For almost anything based on user experience and especially mass-market customer-facing products, human QA is far more necessary. In either case, the optimal operating model is that QA is embedded in your product team. They participate in writing tickets, in setting test criteria and understanding the value of the work being done. "Finding bugs" is a low value task that anyone can do. Checking for product correctness requires a lot more insight and intuition. Automated test writing can really go either direction, but typically I'd expect engineers to write unit tests and QA to write e2e tests and only as much or as little as it actually saves time and can satisfactorily indicated success or failure of a user journey.