USD is more for scenes than models. It's meant primarily for stuff like 3dsmax and blender, and is far more complex than gltf.
It's also not really supported everywhere. Pretty much every game engine lacks support for USD, while most (except unity for some reason) have at least some gltf support.
USD is also, at least as far as I'm concerned, dead in the water. I have never encountered a single USD file in the wild, though that might just be because I mainly only work in blender and godot.
I'm not against USD, and I'd love to see it get some more love, but it serves a different purpose than gltf.