I'm not a fan of Brexit but it is what it is.
I doubt that you are really a fan of all things EU but I am with you on unity being important and I absolutely agree we fucked up that one. I'm pretty sure we mildly screwed our economy from day one of Brexit - simply by inviting mutual tariffs for a smaller entity and losing the unified border.
However: I'm old enough (55) to remember quite a lot of EU history. Do you recall or have been told about wine lakes and butter and grain mountains?