I just used his work as an example there are better games than "The Twist" and I find making models harder than drawing you might disagree but that's my opinion as you need to first draw concept how your model is going to look and then you need to create it and it must look decent in art all you have to do is to draw it and you do not have to bother with modeling.
The dwarf slave path exactly felt as you said "Oh well, it's another beautiful day, let's write some crap to make our patreons happy" it was an unnecessary and weird path which was weird that's why it got cut I agree that they are now finishing their paths and they are no longer trying to create another romance paths but that doesn't change the fact how this game is getting delayed because of their too many paths and I think they have already announced a new game so that also says something about them.
I think creating 4 paths would be enough 1) mother 2) Drow 3) Orc 4) Sandy I even find Death route absurd because of the way how she is interested in you is ridiculous.
I like Death, she is my favorite character although I prefer the looks of the orc. It is just personal preference, I think they are objectively all well written, I did not see anything forced, really.
You are under the assumption that people take their time to draw concept arts and then model everything themselves... That is really far from the truth unless they have big teams or are AAA companies.
I would say the majority has models purchased off Daz3D or somewhere else, other minor objects do not really require concept art... If I had to model a tea cup, I could do that fairly fast despite not having too much experience with 3D.
As for character creation, even if they were to model them themselves from scratch (Very unlikely considering DAZ3D or similar), they would need to model only the base body, that is it.
Different hair styles, morphs, etc. would be things you add to it, it is not like they have to model a character from scratch each and every time.
Same goes for animation, once you rig the base, all the animations you do for that single rig will work for all the other characters.
There is no white or black here, really.
Both 2D and 3D have their advantages and time consuming tasks, one is not easier than the other, this includes Fate of Irnia and whatever other 3D game you have in mind.
The only difference that applies only here (Related to porn games, specifically, from what I have seen) is that 3D has many tools to make your life easier (Character creation, to be more specific) whereas in 2D you either draw the stuff or you do not.
It is the reason why 3D games are so much more common than 2D ones.