i have the same issue (acrobat pro dc). I write a lot in my pdf with a pencil and the erase function is really annoying because it takes me soooo much time to erase words or sentences. In other pdf-editors this is far more easier. Is there really no other option to make the thickness bigger so that can erase faster? Erasing via the comment section is no option, since i would have to search for my comments, that would be insane.
I must say that this is really disappointing, since acrobat seems on the other hand a powerful tool.