There are many measures of success, and if you want to talk about quality of life, by all means look at how bad the discontentment with the EU has been growing over the years, among all member states. Keeping everyone in the EU is not sustainable.
Freedom has a cost, and it seems that the UK populace who voted to leave does not fully understand that cost.
In the US, those are all going the opposite directions.
When countries grow powerful, they begin to forget about the "socio" part of socioeconomics, and just look at dollars.
Clearly a very, very large portion of the country felt underserved by the model.
Nassim taleb sums it up well: http://reason.com/blog/2016/03/15/nassim-taleb-the-global-re...