Problem is that many devs don't take the time to develop a testing mindset (or think it's not their job). QA is a lot more than writing automation or validatin

Problem is that many devs don't take the time to develop a testing mindset (or think it's not their job). QA is a lot more than writing automation or validating code correctness. QA are the first people to lobby on behalf of a customer when it comes to actually using the feature (ideally this is a PM's job, but I've seen few good PMs in the Bay so far). QA also has to think holistically about security, performance, UX, on-screen text like error messages and so on. Hopefully the team has free access to other teams who specialize in this kind of work, but more often than not such resources do not exist or are unavailable. Thus it falls onto QA to fill all these small (or big) gaps.