Aren't frats present at most colleges, and aren't they much easier to get into?
OP isn't asking about "clubs for rich people" which seems what you're reducing this to be. Frats focus much more on providing housing to members as well, don't they?
And it really seems more like an Anglo thing. I mentioned the boarding schools to begin with, because I knew of Eton and the English with their weird stuff. But that's not the same as having these "societies" at every university - and especially not for whole of western Europe.