I’m not saying it’s cool, but here’s the “why” part:

When visiting a *.google.com domain, the Google site can use the API to query the real-time CPU, GPU, and memory usage of your browser, as well as info about the processor you’re using, so that whatever service is being provided – such as video-conferencing with Google Meet – could, for instance, be optimized and tweaked so that it doesn’t overly tax your computer.