Pain in the ass how?
The thing about the deal. ... They ended up with some semblance of free trade. ... no tariffs, no quotas, just demand determining what goods are available throughout Europe. Relatively unfettered.
They could have done that easily a few years ago when the UK said it wanted out, but everyone was butt hurt and intent on throwing road blocks in each others' way. This doesn't seem like a pain in the ass, though, for the average person. They no longer have to cede sovereignty with regard to immigration, work rules, etc. to a bunch of other countries that culturally are different. And the stuff available to the typical consumer shouldn't really differ from what is available now and the prices will remain competitive.