> Most abstractions in software exist because humans need help. We couldn't hold the whole system in our heads, so we built layers to manage the complexity for us.

Kind of a sloppy statement, but I don't think it's accurate to say abstraction or layering exists in software just because humans need help comprehending it. Abstractions often exist to capture the essence of some aspect of the real world, and to allow for software reuse. AIs will still find reusing software useful? Secondly, you equate "abstractions" with "layers" which aren't really the same thing. Layers are more about separation of concerns. Maybe it could be argued layering is a type of abstraction.