At the surface the UK is awfully prudish, but if you take a closer look, it's really just repressed. I.e. horny people pretending they're not horny because they think the other people actually aren't horny and might judge them. Perhaps some may truly judge them. But in the end most people don't give a crap - not enough to create trouble at any rate. And if you do end up in a judgemental environment, just move.
I can't agree with the first sentence, but then I've worked in the US. Personally I have zero interest in whether anybody else is 'horny' or not - it wouldn't even cross my mind and I suspect the majority of people feel likewise
Sadly for a significant number of people it's not as simplistic as 'just move'; sex workers have lost their jobs, homes, and become estranged from families because of their job as well as having to endure harassment from neighbours - it does depend on circumstances and location to some degree, but while I'm happy to have full face pictures in my ads I would never have porn pictures or videos online for precisely the reasons mentioned above.
Plus as mentioned above (and according to the people I know who have done porn) it's unremittingly grim, poorly paid and bad for the health - having to take antibiotics for chlamydia and gonorrhoea practically every month isn't much fun. I've never known anybody move from prostitution to porn, only the other way round. Most people prefer to be able to choose who they have sex with.