Oh boy , this is American exceptionalism at its finest. The US has by far the most authoritarian government of all mentioned entities.
Really you should protest against your government.
Yes, it is American exceptionalism (and quite foolish) to make the claim that "This could never happen in the US".
No, the American government is NOT more authoritative than the UK in the way they handle freedom of websites. The grandparent comment is correct: the US government does not (currently) order ISPs to block specific websites.
Yes, those in the US should protest the current government (many of us already are doing so).
Just looking at the percentage of the population in prison, or murders by cop per inhabitant, that are also good indicators of "repression", and the US might rate first worldwide.
As a note, I think you meant authoritarian; authoritative means “preeminent/most trustworthy”