Not a lawyer, but UK law doesn't apply across the world.
No, but it does apply in the UK, and international law has always been clear that when you serve customers in a country, you do so under the laws of that country.
UK law does not apply to what is served to US customers. It applies to what is served to UK customers. And if you break UK laws, you pay UK penalties.
This has been the standard internationally since Dow Jones vs Gutnick 23 years ago (That was an australian lawsuit that settled how international juristiction works in defamation cases and has been largely adopted internationally as it was based on the US model of international juristiction).
Note also, both OFCOM thing, and Twitters violations in Australia are both related to websites (4chan and twitter) refusing to provide information to cops doing child porn investigations.
Thats what these companies are protecting. Nothing to do with politics. Its pedophiles, not politicians.