Unfiltered web browsers might be harder to come by these days than when I was growing up, but they still exist. I remember finding out by accident that certain restricted apps would pull up help pages, and from there I could click a link that would take me to an unrestricted web browser due to a bug in the code. I also remember computers where you could show up with pocket apps on a floppy or USB key and bring your own unrestricted web browser. On top of that, just because the web is restricted often doesn’t mean YouTube is restricted. For example, schools need YouTube to show educational content, so it often is unrestricted even when the rest of the web is restricted e.g. by dns.