But let's assume Bob continues to have an active role, because the people above him bought in to the hype and are convinced that "prompt engineer" is the job of the future. When things inevitably start falling apart because the Bobs of the world hit a wall and can't solve the problems that need to be solved (spoiler: this is already happening), what do we do? We need Alices to come in and fix it, but the market actively discourages the existence of Alice, so what happens when there are no more Alices left? Do we just give up and collectively forget how to do things beyond a basic level?
I have a feeling that, yes, we as a species are just going to forget how to do things beyond a certain level. We are going to forget how to write an innovative science paper. We are going to forget how to create websites that aren't giant, buggy piles of React spaghetti that make your browser tab eat 2GB of RAM. We've always been forgetting, really - there are many things that humans in the past knew how to do, but nobody knows how to do today, because that's what happens when the incentive goes missing for too long. Price and convenience often win over quality, to the point that quality stops being an option. This is a form of evolutionary regression, though, and negatively affects our quality of life in many ways. AI is massively accelerating this regression, and if we don't find some way to stop it, I believe our current way of life will be entirely unrecognizable in a few decades.