The western world was already the most advanced and richest part of the world before they started colonizing, which indeed made them even richer. Note that the people they conquered whether it were the Incas or else were also empire with colonial ambitions, except they were way less advanced.

You've got the causality wrong. Europeans exploited other peoples because European societies were more advanced. They did not become advanced because they exploited.

The United States seemed prosperous enough even in its early days. Even though it had to pay taxes and such to Britain.

I guess the best argument along those lines you could make is that the US depended on imported slaves.

Also: took land and resources from native Americans and developed and exported them.