If all I do is host a website that serves images, and I'm not hosting nor operating out of the UK, why would I be subject to their laws? Just because it's accessible globally means I now have to factor in every possible regulation from around the world?
The burden shouldn't fall on me, the website operator, to block UK traffic because they want to restrict content or enforce age verification. Nor should they be able to fine me. It's up to the UK to have UK based ISPs block my site then.
Obviously a different story if I'm deliberately offering a paid service to UK citizens, or advertising to them, etc.
But to suggest that every website owner now needs to be aware of, and follow, ever nation's unique regulations will spell the death of the internet as a global network.