Come on then, Nigel, list out the benefits we’ve all received as a result of BrexShit I'm guessing that 'out' should be 'one of', and that you are unable to spell 'Brexit', But:
Increased fishing catch limits

Also, the ability to decide for ourselves what action we take to control visitors from China since the relaxation of their travel restrictions. (Covid protection) Here. The EU claim to work as a bloc, but are making decisions piecemeal. Italy were the first to bring in restrictions, but thanks to Schengen that does not prevent Chinese visitors entering Italy through other EU countries.