You are not wrong, but Zuckerberg was competing against thousands of people with just as much privilege as himself (and some with a lot more). All of that same privilege didn't guarantee the Winklevoss twins success.

Obviously you can't have a billion dollar company if the country you live in uses a different currency.

The only one of those that has anything remotely approaching reality is being born in the US, or another first world country. Had he been born somewhere in undeveloped 3rd world, or somewhere torn apart by war, we likely would not be talking about him.