There has never been a more fertile environment for motivated learners to do more with less, and yet we still have a bias as an industry to seek the more experienced hand versus the energetic one.
Also possibly, good would-be-junior-devs find something more productive to do.
People are focused on absolute llm accuracy, but time-to-90%-there for AI vs junior dev is seconds to hours/days.
These people were exceptional outcomes, where luck and hubris met sufficient competency. You cannot argue the general case from exceptions.