Agreed that LLMs can make the role of junior developers become one of filtering out bad LLM output, and tuning a prompt until it outputs the right thing.

I think the concern that we won't have senior developers later if there are no junior developers now, is pretty valid. The question is if LLMs will keep up pace to replace senior developers when the current ones retire. Since no one can predict the future, it's a pretty risky gamble at the scale of the entire industry. (OTOH if this new tool sparks more interest in the occupation, then maybe the issue solves itself by sheer numbers.)