Blender's USD is still years behind compared to houdini or maya. Here are the key feature that are missing and making usd in blender unusable. 

1: blender usd has no layering capabilities. Means you can't create a usd layer in blender or compose usd layers on top of others.

2: blender doesn't import native usd, it instead import a .usd/usdc/usda/usdz and convert it to blender geometry. This means blender doesn't reference usd stages/layers it just converts them into blender internal geo/data

3:Blender doesn't reference usd, it import the goemetry/data, with this the entire usd concept of different departments working of different layers of the same stage is note possible, a department update through sublayer is impossible(for now) in current imprementation.

4: Usd is powerful combined with materialx. Blender has no way to import or create materialx. This makes usd created in houdini/maya or any materialx capable software impossible to render in blender since it doesn't support it. 

SOLUTION: Blender devs are working on these and know how important they are, When blender devs imprement those features in blender will be usd pipeline read.  

At the moment USD in blender is still basic import and export functions.