and based on kiinda conservative assumptions, ai coders start being competitive in 2028
That's true only for the HR department. Because code and experience wise, someone that has been programming for 5 years isn't that much experienced than someone fresh from college. In 5 years you barely have time to get to know your editor inside out, and start to have a grasp on your first tech stack.
I consider someone to be an experienced developer one that has seen a couple frameworks and hype cycles come and go. Let's say 10 years of experience.
Also, AI has 0% productivity. Being able to churn out code without being able to reason about it in the grand scheme of things makes it worse than even a non-programmer in problem solving ability. AI has no problem-solving ability. Ignoring this issue makes the whole thing moot, because it assumes that GPT is actually AGI.
sure you draw the line where you feel comfortable, but in the US job market, people get the senior title in 3-7 years, its just a statement of fact rather than opinion.