People aren't advising junior engineers to not use AI at all. They are telling junior engineers that AI is a force multiplier, not a replacement for understanding.
They are telling junior engineers that without fundamental knowledge, these junior engineers will just will blindly accept whatever hallucination AI feeds them.
They are telling junior engineers that without understanding the fundamentals, a good prompt is hard to write, and it's even harder to supervise/validate the work.
They are telling junior engineers to focus on learning what matters and use the AI to help, not hand over the keys and stop learning.
At least, that's what I'm telling them.