We were stuck near local maxima since before LLM's came on the scene. I figure the same concentration of innovators are gonna innovate, now LLM assisted, and the same concentration of best-practice folk are gonna best-practice--now LLM assisted. Local maxima might get sticker, but greener pastures will be found more quickly than ever.
Honestly the biggest hindrance of developer productivity right now is probably perpetual, looming layoffs, not lacking AI, tools, programming languages, etc :)
I expect it'll balance.