It depends on the website hosting location. TOS,, users location and relevant international copyright treaties.
It's not a one-size-fits-all.
As a UK citizen I can't claim my (US) first amendment right to call you a "cunt".
It's against the website TOS and I'm not American.
Putting a license at the bottom clears any ambiguity.
Funnily enough you're only highlighting your own "Zoomer" naivety of law by making your "Boomer" comment.
Dunno about anyone else but personally: I don't care because I can't afford food each month. Worrying where your next meal comes from focusing your mind somewhat.