I think it's great to push back against the import of US media and greatly encourage more home-grown content but I also think that blaming US media for changes to children in the UK feels a bit like not taking responsibility for the shite on our own doorsteps.
I'm American and British. I have a mixed accent, and so do my kids. I've more than once had to talk to schools about staff making anti-American jokes in class because it was inflaming bullying against my kids. I've more than once had complete strangers get aggressive with me and my kids because they don't like how we sound, young and old alike.
I don't know any Brits who want to be any type of American, the closest I've had is people telling me where they'd like to go on holiday. The current increase in brain drain of young people who are educated in the UK and leaving as young adults has little to do with US media, and more to do with how remote work has grown. Most aren't fleeing to the States, they're going to places like Thailand or Bali.
As I said, limiting US media and replacing it with more home-grown content and good role models is great, but let's not pretend that the issues we're having with kids and the rest of British life is really about what the US is exporting. That's a copout.
The US has infiltrated the UK in plain sight and at a much wider level.
I think the UK and most of Europe infiltrated what is now the US, and some of what those Europeans made found their way back, much of it changed.
"Britain sent their religious nutters to the Americas and their criminals to Australia. By far and large the criminals have made a much better job of it!"
A common joke; however, Britain sent more convicts to their penal colonies in what would become the US, than they did to Australia or any of the other penal colonies.