[dotnet00]

It's probably because high quality 3d is just much more expensive to do. You can easily do all sorts of effects in the constrained environment of a 2d model that take a lot more skill to pull off in 3d.

Plus, ultimately, the anime aesthetic is a 2d thing. It's a lot harder to make a 3d model look good in a 2d art style, as a ton of anime over the years have shown.

[numpad0]

A lot of them had 3D models and quit using it. So I doubt it had to do with the cost of making one. IMO the second one is much more likely.