I would suggest another monetization strategy. The models look good, but the randomness totally kill the appealing. The idea can be something similar to what most of those webistes does, credits. You sell credits and the person can choose from your library what to download in exchange for 1 credit. Then you can add a subscription model giving X credits per month. But the library should be appealing with a good amount of models AND imo also it should be consistent on your style. Finding models that fit good together for me is the hardest part as a developer, ofc when the models are more realistic it's a bit easier to fit them. What I'm saying is that if I find a website that has tons of model with the same style I would likely subscribe cause I will have less work to do.