https://www.nytimes.com/2021/09/28/world/europe/brexit-britain-fuel-johnson.html
One of the reasons the EU zone worked was that people could travel from the less developed parts of Europe to the more developed parts and get jobs doing things that the British, French, Swedish, German, et alii didn't want to do, meanwhile earning more money than they would have in Romania, Greece, et aliae. Now that system ISN'T working for the British -- and they're finding out that they miss at least some of it.