IMHO, Brexit was mostly an exercise in placing the blame in a single “entity” instead of circumstances. Fishing gets harder due to over fishing. Technical advantages and industries moving have made certain classes of work such as mining and steel factories redundant or moved to other (cheaper) locations. This left a lot of the lower income classes and many middle income classes which jobs depends on servicing the lower income (restaurants, clothing, automotive industry, etc.) hanging in the wind.
Then instead of accepting the changing circumstances of the world, it is blamed on a single entity “EU” that is single handedly causing all their woes. Just leave and your lives will be better. Well, they learned.
This is how you get people to vote for someone like trump. They claim it is all the fault of some X, get people riled up, promise to fix X, get voted, and then you have to actually make their lives better.