As someone from a country still in the EU the Brexit outcome makes me uncomfortable. It is clear now that the EU is a set of golden handcuffs for those on the inside. As the EU grows in power it dictates more and more rules. I’ve heard numbers as high as 80% of national legislation being determined by EU directives. Mostly I think the EU directives turn out better than the national legislation would have (we would never get such strong privacy rights for example), but this might not always be the case. When those golden handcuffs start to chafe, what is a member country to do?
The EU has a real challenge ahead in leaving a place for regional and national self-determination, and ironically an EU constitution might be the best path to limiting its power, just like the US constitution somewhat acts to protect the states from the federal government.