Because the author has something to say and needs help saying it?
pre-AI scientists would publish papers and then journalists would write summaries which were usually misleading and often wrong.
An AI operating on its own would likely be no better than the journalist, but an AI supervised by the original scientist quite likely might do a better job.
I agree, I think there is such a thing as AI overuse, but I would rather someone uses AI to form their points more succinctly than for them to write something that I can't understand.