>>362214917
Nothing about Mecanim is optimized, it's literally a decade old third-party plugin that they decided to put into Unity at some point and then literally never touched again. As evident by the fact that we still need Harmony patches for the editor to make the Animator UI work nicely.

The only thing they were able to "optimize" about Animators is that it now uses Jobs to run the state machines internally, but it still has to join back to the main thread to apply all the transforms (which is probably the brunt of the perf issues).

You can actually get around this performance issue completely with the "Optimize Game Objects" option while setting up the rig, but you currently can't use this in VRC because the IK needs the actual bones to work. And of course, this would also prevent you from animating hair or clothes bones.

For real though, install Adv Safety and disable Animators. Everyone will look broken, yes. You'll also suddenly be pushing 2x higher framerates.