Now with AI, I expect junior developers to learn much quicker and progress to senior very quickly. I'd now rather hire at least 1 of each to begin with, both "junior" and a "senior" developer and then additionally hire more juniors to quickly turn them into a "senior".

We do not need to hire anymore outside senior developers who need to be trained on the codebase with AI, given that the junior developers catch up so quickly they already replaced the need to hire a senior developer.

Therefore replacing them with AI agents was quite premature if not completely silly. In fact it makes more sense to hire far less senior developers and to instead turn juniors directly into senior developers to save lots of money and time to onboard.

Problem solved.