Software engineering is a lot more social and communication-heavy than people think. Part of my job is to _not_ take specs at face value. You learn real quick that what people say they need and what they actually need are often miles apart. That's not arrogance, that's just how humans work.
A good product manager understands the biz needs and the consumer market and I know how to build stuff and what's worked in the past. We figure out what to build together. AIs don't think and can't do this in any effective way.
Also, if you fuck up badly enough that you make your engineers throw out code, you're gonna get fired lol
A human coder can be seen as an abstraction level because it will talk to the PM in product terms, not in code. And the PM will be reviewing the product. What makes this work is that the underlying contract is that there's a very small amount of iterations necessary before the product is done and the latter one should require shorter time from the PM.
We've already established using a LLM tool that way does not work. You can spend a whole month doing back and forth, never looking at code and still have not something that can be made to work. And as soon as you look at the code, you've breached the abstraction layer yourself.