And junior programmers

...no. Juniors are hard enough to mentor to write sensible code in the first place adding AI to that is only making things worse.

The long-term impacts on AI past what's already happening (and having an actual positive impact on the products and companies, that is, discount that Hollywood scriptwriting stuff) will be in industrial automation and logistics/transportation. Production lines that can QC on their own as well as a whole army of truck and taxi drivers. AI systems will augment fields such as medicine, but not replace actual doctors. Think providing alternative diagnosis possibilities and recommending suitable tests to be sure kind of stuff, combatting routine tunnel vision by, precisely, being less adaptive than human doctors.

Any platform that does that is going to collapse. Not enough people will watch AI generated garbage for it to be viable, and those that don't will simply split off the internet and entertainment, shrinking and splitting the economy.

I understand that they'll be replaced, or at least the producers want thant, but I don't think that's because of repetitive work, more like they need a lot of them.