I'm a remainer but I think little nation states that are non EU like Switzerland or Singapore survive and prosper quite well.
I admit I don't know that much about the EU - I think of it mostly as an admin for free trade and travel between the countries mostly. Which I quite like.
One of the troubles with the 2016 leave/remain referendum was remain is clear enough but no one really knew what leave would consist of. When you clarify it none of the options are very popular for instance the polls on remain/May's deal are about 60:40 to remain. Even remain/no deal polls about 56-44 towards remain so to leave politicians will have to force it through against the wishes of the majority of the people and of their parliament. Which is kind of a mess.