At the rate things are going, even EU and Schengen, areas in which their citizens are blissfully unaware how nice they have it compared to outsiders, are going to come to an end. Far-right nationalists are on the rise over Europe.
They just lost ground in the Netherlands, losing about 1/3 of their voters from last time (down from 24% to 17%)
It doesn't even take the far right winning to unravel the EU. Both France and Germany, the economic pillars of the EU are facing massive budget challenges due to aging populations, high energy costs and trade
The European far right are not exactly fans of the EU, but on the whole they are much more concerned about immigrants from low-trust Muslim societies than from EU countries (high-trust "Christian" societies)