True, and very much the case with games that has the porn as the focus.
But DeLuca is not (solely) about the porn. There is no 'buildup'. For there to be buildup it requires that the end goal with all the interactions is aimed towards sex in the end.
But here the sex is not the goal- it's just part of the journey. It will just happen as you progress with the girls naturally. You interact because you want the story and learn about the girl. After sexual interactions, the next interactions will still be about the story and the relationship between them.
Of course, in this marked, that style is classified as a niche and perhaps I would gain more patrons by following the popular formula. But I enjoy what I do and I'll stick with it.