It all used to be smoking and there are still places in the world where trains and busses have seats facing each other. Having sat in those seats in the past I can tell you that people can still perfectly well not talk to each other ;)

There are cultures (e.g. go to Israel) where random people still talk to each other.

I'm not sure I would call what you observed in Europe privilege. I think you were just an outsider/immigrant from a different culture. Different places have different cultures and it takes a long time (if ever) to acquire them. You'll be treated differently if you don't have the right social cues e.g.

In places like the US or Canada this tends to be a lesser effect because it's a big melting point.

I know plenty of really rich people (like billionaire or approaching) that aren't that different than most of us (also rich). You don't magically move to some other "circle" just by having money. It's true there are certain "classes"/cliques in different cultures but it's not as simple as has money vs. hasn't.