> The continued reliance on say, COBOL, and the complete lack of those developers comes to mind.

So the irony here is that LLMs are actually going to be decent at COBOL by default. And other uncommon/esoteric codebases. For example I vibe-ported some Apple ii assembly to modern C/SDL and... it works. It's stuff that I just wouldn't even attempt at manual development speed. It may be actually an easier path than training someone to do things, as long as you have a large enough test suite or detailed enough requirements.