Biggest reason people voted leave, was so we can hire and fire, at the ballot box, the politicians that set UK political policy & make our laws.
Where politicians & parties get stale and more corrupt (with power) over time, it is vital that you can then replace them in smooth transitions of power and they don't stray too far of an acceptable political path and that the legal system and enforcement is independent of the government and executive.
None of this applies in dictatorships including the one that is steadily growing in power in Brussels. I'm sure that national politicians think they can control a much more extreme (especially an increasingly hard right wing Brussels) with a big army, police & judicial system under their control, but an important lesson in history is that is what Franz von Papen said he would do to control Hitler and we know how that one ended.
I hope when the EU fails it does so reasonably peacefully and doesn't cause too many wars with their neighbours like USSR/Russia has. The UK has spilt enough blood and treasure having to sortout two centuries of mainland European geopolitics and wars, with no thanks from the people we helped, we don't need any more of this.