Sure, they could do that. The outcome wouldn't change, though.
If SW devs who worked on ride sharing apps didn't leave, why would you think these folks would?
If SW devs who worked on airline ticket search engines didn't leave, why would you think these folks would?
And on and on and on. The SW industry has been heavily involved in replacing jobs since its inception.
> The SW industry
Partly the issue is, it was never the right model.
If you write/wrote code, you were a manager. Probably a better one than your "people manager" ever was, but that is/was arguably a different skill. What you managed was extremely technical, more akin to a line manager or an operations manager than a people manager.
Which, yes, everyone could not be the manager. Everyone who was not the manager could be quality control (QC), and handle the parts that "only a human" could handle.
The problem is, AI fits in nowhere in this equation, rather it throws it out. AI can manage, like any manager it can short circuit it's QC, in pursuit of an arbitrary metric. Even the idea of "human in the loop" is fundamentally flawed - if the human is not at some level the one directing (managing), there is no reason to stop incuding the human, less and less, in the work.
AI is not useful to us.