Aside from ease of crossing between nations for tourism and such, what complexity is required, and for what advantage? Complexity obviously isn't an inherent good. From what I can tell, the UK has had a negative trade deficit for most of the last 30 years, so would it be even worse without the EU? At least in the case of NAFTA, trade agreements turned our economy from having a milf trade surplus with Mexico to having a massive trade deficit that has never gone away. I'm not even particularly anti-free trade, but obviously lower/middle-class workers in manufacturing are going to be worse off when poorer economies are given easier access to compete. While it will certainly become more expensive for the UK to trade with EU members,
there are still plenty of goods brought into the EU by non-member nations (the USA apparently imports more than all member-states combined unless I'm reading that chart wrong), so I'm doubtful that the barrier-to-entry will go up by that much, unless the EU decides to be punitive. From what I can find, the citizens of the UK don't appear to
personally profit as much as other Western European members of the EU either.
Maybe altogether this signals something inherently broken with the UK's system and that the EU is merely cushioning what would otherwise be a much larger problem for them, but I dunno, I'd like more concrete information showing not only how the EU is specifically beneficial, but also something over the UK's lengthy membership showing how it got them out of a bad situation.