In my own country, for instance, businesses have benefited greatly from the single market and the euro. Due to lagging wage growth and an increasing tax burden, however, the benefits for households are less pronounced.
If a large proportion of them start to see “Europe” first and foremost as a private party for businessmen, with scant benefits for their own pockets, then that will undermine support for the European project. I think that is something we should all be worried about. Also, because Europe is about so much more than just the financial benefits.