The way it always seemed to go for me, when I was in that role, is the product is already complete, development is done, you're handed all the tests/etc that the disinterested developers care to give you, and you're told to make those tests presentable and robust, and increase test coverage. The process of doing that inevitably uncovers issues, but nobody cares because the thing is already done and working, so what was the point of any of it? The point was just to check off a box. At companies like this, the role is bullshit work.