It proxies content, so whatever it can get from YouTube should be displayable, my guess is that its possible but most instances do not enable it for bandwidth and performance reasons
A piece of software that anyone can host on the internet which allows you and others to watch YouTube without loading their original page full of ads and anti-features, whilst also allowing you to have a certain level of anonymity and improved privacy.
(the anonymity comes from collective anonymity, where you’re harder to make out in the crowd, as YouTube only sees a bunch of people watching a bunch of random videos, but not who is watching)
by “most of the internet” I mean a HUGE majority of the websites you interact with being hosted on servers that run, you guessed it, Linux. Additionally, your WiFi router probably runs linux, almost any non-iPhone runs Linux, IOT devices (say, security cameras) usually run Linux, and Linux is even on Mars.