In my experience newcomers and junior engineers don't get better by writing more bad code. They learn mostly by 3 methods. 1) finding flaws in their code the hard way (slow) 2) getting careful feedback from more experienced people (has to be done well) and 3) reading better code for a problem they already understand.

I'm not sure GPT helps with any of those yet, as it seems to be more likely to spit out incorrect-to-sortof-okayish so far.