We talk about a lot of different things -wealth, status, security, happiness, absolute gains and relative gains eg- when we talk about this stuff. I think it very important not to lump all sorts of things together, and then identify a single explanation for them all. UN figures suggest that a massive chunk of humanity has been lifted out of absolute poverty over the last few decades. The material baseline is getting higher.
I was a Brexiteer -still am. But actually existing Brexit was a fuck up, the costs of which are easy to see, the gains of which not so much. We should have edged out, but the manner of our departure hugely strengthened the hand of those committed to the European project, and weakened those who shared our/my skepticism. On the EU, let’s see how things look in10 years, but for now, the future of the EU is far down the list of Europe’s, including Britain’s, problems. If the US pulls back from Europe, then European states will have some very difficult guns or butter choices to make. If they choose butter, they will have to appease Putin. And if they appease Putin, this will have a profound effect upon their own internal politics. Ugh!