We had a Brexit because the government hadn't appeared to listen to the concerns of the people. Or if they had listened at all, they'd done little to solve the problems. Whether those concerns were valid or not was not the issue. Those concerns were never dealt with, other than a glib PM paying lip service occasionally. People felt that they were being micromanaged by the EU in too many sections of their lives. They also felt that the country's infrastructure was breaking down because of the surge in population. They felt too that their national identity was being eroded, although that wasn't such a big deal to the younger voters. They didn't feel that their concerns were being taken seriously and could see no end in sight. So finally they lost patience and walked.
Maybe they were right to walk. Maybe, if they'd been genuinely listened to and reassured, they might have stayed. Or just maybe the EU has become so intractable and beaurocratic that there really was no other choice. Shame.