What is making it difficult for Junior devs to be hired is not AI. That is a diversion.
The raise in interest rates a couple of years ago triggered many layoffs in the industry. When that happens salaries are squeezed. Experienced people work for less, and juniors have trouble finding job because they are now competing against people with plenty of experience.
Simple, there are always people who are intentionally using the hard way. There is a community programming old 16-bit machines for example, which are much harder than modern tools. Or someone learning assembly language "just for fun".
Some of those (or similar) people will actually learn new stuff and become senior devs. Yes, there will be much fewer of them, so they'll command a higher salary, and they will deliver amazing stuff. The rest, who spend their entire carrier being AI handlers, will never raise above junior/mid level.
(Well, either that or people who cannot program by themselves will get promoted anyway, the software will get more bugs and less features, and things will be generally worse for both consumers and programmers... but I prefer not to think about this option)
And even if it could, how do you get senior devs without junior devs? ^^