Peace has been kept by NATO, what peace there has been.
Justice? Whose justice exactly? That which offers access to courts on the basis of innocent until proven guilty or the one that has put itself above any UK laws and assumes guilt with the accused having to prove their innocence ( the European way).
As for prosperity - tell that to the Greeks, the Spanish, the Portugese, the Italians or anywhere else with youth unemployment in EU countries running at around 49% and of course many with collapsed economies. Even Germany is in recession. The banks are broken. The EU ha no accounts for 15+ years. No accountability
A really good job done there.
All over Europe and especially in EU countries there is unrest - France with its Yellow Coats, Spain and the Catalans, The rise of Antifa which is stronget in continental EU than here.
No internal borders - has that promoted prosperity and good for us? Diversity? Respect for other cultures - ask the Swedish about that one or even the Germans, whose culture is being respected in a state where there is no cultural identity for its member peoples?