Yeah, that would be very helpful to track. Anecdotally, I have found in my own projects that the larger they get the less I can lean on agent/chat models to generate new code that works (without needing enough tweaks that I may as well have just written it myself). Having been written with models does seem to help, but it doesn't get over the problem that eventually you run out of useful context window.
What I have seen is that autocomplete scales fine (and Cursor's autocomplete is amazing), but autocomplete supplements a software engineer, it doesn't replace them. So right now I can see a world where one engineer can do a lot more than before, but it's not clear that that will actually reduce engineering jobs in the long term as opposed to just creating a teller effect.