Second, European middle class is already pretty juiced. Total level of taxation is pretty high and real estate is becoming unbearably expensive. This is a huge problem; with some exceptions (Germany), Europeans think of themselves as middle class when they own at least one home or apartment, and this used to be well possible until at least 2015. But a combination of overregulation (not enough being built) and cheap capital is killing this dream.
It in fact does not contribute to the EU programs it didn't elect to willingly, that's one of the perks of EEA.
https://www.regjeringen.no/en/topics/european-policy/Norways...
A few generations ago, many people paid of their mortgage within 15 years of buying property. Now, it's usually 30-40 years due to the rapidly inflating prices. It's obvious, to me at least, that this contributes to higher private debt.
Direct and indirect contributions to EU coffers are minimal as % of state expenditure, particularly once you look at the outsized returns in the wider economy. When German banks lend money to Greece to buy their tanks, public debt exposition grows in theory but in practice German coffers win twice. That's why Northern European countries are the big winners of the Common Market. If you have an issue with how this dynamic allocates the resulting "loot", you should take it up with Northern European leaders who allow most of the returns to stay in the private sector.