Realistic porn is an already existing subset of porn. A maybe counter-intuitive effect of filmmaking is that well-produced films in the likes of x-art.com appear more realistic and cute than what amateurs upload. A good director will make us forget that the camera is there and that it's all staged.
To me, X-Art and similar producers always felt like the other opposite of fake porn. It's not harsh and violent like plenty of mainstream porn, but the participants are still very much acting for the camera.
I think the only website I know where, even tough they never try to disguise it as non-porn, the participants actually seem to enjoy themselves consistently is Abbywinters.