how does Europe fund its generous welfare benefits?

simple: https://en.wikipedia.org/wiki/List_of_sovereign_states_by_tax_revenue_to_GDP_ratio

France's tax revenue is 46.2% of its entire GDP. for Sweden, it's 44%. for the United States, it's 27.1%. for Nigeria, it's 3.6%.

the further down the list you get, the lower the taxes are, and the worse off the country is.

i'm not saying that if you just turn up the taxes, this will fix everything. but it's an observation...