Animators area huuuge reason VRChat performs so poorly, mainly as FX layers stack up. FX layers, while cheap, adds animator idle time linearly. Blend trees while more expensive due to typecasting most times, seems to be the way to go to avoid the mass load of layer idle timers.

All this comes down to Compute Time, it can be labeled as "Active Animator Time", measured in either Microseconds or Milliseconds. This can be done on the server as animators are single thread and most single thread workloads on servers are generally about as slow as a mid-range VR PC, and thus the time it takes to compute on the server then gets graded into Excellent, Good, Medium, Poor and Very Poor ranks, with a hard compute time limit (Medium or better?) set on mobile platforms like Android, iOS, and Quest Standalone which don't have as much CPU horsepower.