>>415971483
It's not Unity, it's all the shit that the VRC devs tack onto player objects. Coupled with the fact that Animators are always running, you're looking at a lagfest.
Unity has its shit moments, but holy fuck is it painful to support user-generated content in alternatives like Unreal Engine. Let alone the fact that Unreal is not VR-friendly and you have to struggle against some core UE concepts and workflows to get VR to play nicely.
There are other Unity games (like CVR) which show that you can optimize a game like this. Even Lavender, despite how scammy and mismanaged the whole project was from the start, showed that you can have lots of people in an instance with basically no lag.