> One other thing that surprised me was that my eng manager was seemingly oblivious to my ongoing complains about growing cognitive load and confusion rate.

Engineering managers in my experience (even in ones with deep technical backgrounds) often miss the trees for the forest. The best ones go to bat for you, especially once verifying that they can do something to unblock or support you. But that’s still different than being in the terminal or IDE all day.

Offloading cognitive load is pretty much their entire role.