The pattern I see time & time again in software development: a small set of few and usually very talented senior developers build a software project and they build examples of how everything is done. Junior developers then extend those examples, eg: "add another column to this table." Juniors are just extending the existing patterns, seniors are the ones that create them.

This pattern I see play out time and time again. Senior builds the integration to various team services, then juniors tweak & mimic those to do more.

> let's say that a senior developer could produce N units of work per Y units of time.

So, it's more the case that senior developers are building full production assembly lines, that can then be replicated to do similar things relatively easily. The cost of the units of work are not at all equal.

How does this apply to AI? Good luck getting AI to do something novel, by definition it can't. OTOH, extending an existing pattern is trivial for a senior developer to do after they have built that pattern; juniors spend a lot of time at it cause they have to learn everything.

So, who is the AI going to replace? If the junior, then you have a senior developer using an AI to do something that is already trivial for them to do. No way AI is replacing the senior.. So who? Who is getting replaced by the AI and who is using it?