Thinking that you are operating in the UK because a UK user can theoretically send packets to you, is similar to thinking a corner store in Japan is operating in the UK because a brit can theoretically get on a plane and fly there to shop.
I run a site in the US and have zero intention of implementing GDPR or geoblocking anyone. If the feckless EU bureaucrats don’t want me serving Europeans, they can either block me or convince their citizens to stop requesting things from my servers. Beyond that, they can fuck off.
I travel internationally all the time, including to Europe. These clowns don’t even have the ability to connect me to my site. They can’t subpoena anyone, they have no control or visibility. Why does anyone outside of the EU give a shit about this? It baffles me.
You can declare that “it doesn’t work like this” all you want, and I’ll just keep ignoring it. GDPR is totally irrelevant to me, and no one who disagrees has the power to actually do anything about it.
If I offer a service in US I still have to respect US law, it doesn't matter that I'm based in Luxembourg or New Zealand.
The same applies in reverse.
E.g. many US news outlets never cared to implement gdpr and geoblocked European users from accessing their websites.