Yeah, I think about it sometimes, too.
But there are too many things.
You have to get consistency in generation, or use sprites. Like Bones does, for example. Next, animations. Yes, it's a pain not only in 3D, but also in AI. Good animations are not made in a couple of clicks. You have to do it manually in some editor.
The second problem concerns the code part of the game, but I think it's easier than making good graphics.
The third problem is the story. If we make a parody game, we save a lot of time on plot development. Another issue is that writing a new story will take a decent amount of time.
Of all the problems I've described, the biggest one for me is generating pictures, animations, and consistency. I tried doing rough drafts but they seemed cringe-worthy to me.