What I had in mind when I wrote that line were such prominent cases as My Hero Academia and Dragon Ball Super. (Since I had watched some more of both last night, they were on my mind.) Obviously these programs are more complex than simply being power fantasies (especially in the case of My Hero Academia), but I'm talking about what, if we're approaching this in an intellectually honest fashion anyway, is clearly the main purpose of a given show.
You referred to "Japanese animation." You can't say that and then ignore the fact that about half of the anime produced each season isn't about fighting at all. It's like saying you watched The Avengers, then made an argument claiming that live-action cinema is mostly about superheroes.
My three favorite anime from last season. Power fantasies they are not.