But can you mentally "keep hold" (for lack of a better term) of those tasks that are getting executed in parallel? Honestly asking.

Because, after they're done/have finished executing, I guess you still have to "check" their output, integrate their results into the bigger project they're (supposedly) part of etc, and for me the context-switching required to do all that is mentally taxing. But maybe this only happens because my brain is not young enough, that's why I'm asking.

The type of dev who is allowing AI to do all of their work does not care about the quality of said work.

I think the difference is that you're applying a standard of correctness or personal understanding of the code you're pushing that is being relaxed in the "agentic workflows"

I have the AI integrate their results themselves. That's if anything one of the things they do best. I also have them do reviews and test their own work first before I check it, and that usually makes the remaining verification fairly quick and painless.