Hard to predict. In the areas I know well LLM don’t improve my productivity that much but they allow me to do something in areas I don’t know well e.g. write code in an unfamiliar language (likely bad code but sometimes that better than nothing). So maybe juniors + LLM will replace middle level developers.

Job market is better for seniors right now but that’s mostly because employers can sometimes hire a senior for money they would pay to a junior during late COVID boom.