I'm not sure whether this is still the case, but the cardboard boxes that McDonald's packages its burgers in in Australia used to have '100% Aussie beef' printed on them, but the beef was actually imported from South America by a wholly-McDonald's-owned subsidiary called '100% Aussie'.
Restaurants are free to advertise that they use domestic chicken. You can even legislate mandatory labeling if you're so inclined. The fact that you think consumers need to be actively prevented from getting US chicken, because they don't have the capacity to decide for themselves contradicts your claim that "Brits are NOT having it".
it's classic dumping, the sort that Trump gets upset about
the US is free to make non-chlorine chicken, and then sell it to places that demad non-chlorine chicken
No. A society, which has chosen its government, has decided that it would like to outsource the individual work of tracking food provenance and safety in the form of ensuring that the only food available is food that meets the standards that the society has decided to set.
This is specialization at work, which is in fact one of the primary drivers of civilization and progress.
No one is saying that people can't make these decisions by themselves. People are saying they do not want to, especially in an environment that is heavily information-asymmetric.
I'm a well-educated, intelligent software engineer. Sure, I could go looking into the details of the production facility for all of the meat that I buy, maybe, at the grocery store - but I certainly don't want to. And if I go to a restaurant, I absolutely do not want to have to spend hours researching their supply chain first.
This is not incapacity. This is intelligent division of labor.