Actually they can do it from home Hololive actually demonstrated this a few years ago: https://www.youtube.com/watch?v=nARBc054hjQ
From what I can see its HTC Vive equipment.
4 Trackers (Head, Legs, Waist) and 2 controllers to track arms and control stuff and 2 base stations.
You can go onto the Vive website and find the cost of each item, Each tracker is about $170, each controller is $240, each base station is $330
There are other accessories required such as cabling and the body straps for the tracking but roughly around $2000.
Not a super expensive setup for the amount of dough they are raking in.
But that video was from 2018 I could be wrong and they using mocap suits like Xsens either way It's possible to do full body from home.