The problem with them is there is only like 5 different ones out there that match a composition well enough to be "maximum sexy mode" in an image, and once you've drawn them all once, you basically either have the option of just repeating it over and over or using some sort of lesser pose that won't be as fap fap fap. And since the whole purpose of a porn picture is fapibility you get stuck pigeonholed in.
The only other thing you can do is just blatant close up shots of genitalia which is also pretty boring.
Updated by user 59725