To me the difference is humans (ideally) will learn when they build something in a non-optimal way, and so will improve over time to become a competent engineer / architect. We cannot be perfect but to me a huge part of life is learning from failure and improving yourself, something that LLMs short-circuit and cannot replace.
LLMs cannot truly learn and so are destined to produce whatever the "average" software looked like at their training cutoff, or worse to produce code based on _other_ LLM generated code.
Ouroboros eat your heart out