[klyrs]

Because youtube hasn't siezed it from them yet?

What I'd want to know is what percentage of netizens* even know that you can just add stuff to a url willy-nilly.

* as I type this word, the cognoscenti can literally hear my bones creak

[michaelteter]

Typical people don't add stuff to a URL, but if they see a link that says "youtube.com/playlists", they will probably not expect it to be some garbage channel not affiliated with Youtube.

[andersa]

The typical user will never see the url because they use the YouTube app on their phone.

[LadyCailin]

A related topic that probably most people don’t know about is the public suffix list. https://en.m.wikipedia.org/wiki/Public_Suffix_List