Most of the academics I know will freely state that it only makes sense to go into academia for fame, not for money- and so it's not clear to me what you think the EA benefit is.

The goal is to get direct impact by doing high-impact research. One of the key points here is that donating money is just one particularly straightforward way to do good!

Academia is, in my mind, the textbook example of people doing something because it's familiar, not because they've searched for it and it's the right choice.

I have certainly seen this before, although I think it's less prevalent (but by no means absent) near the top.