Going by individual income, 75% of Americans make less than that. Only one-quarter are in the global top 1%. Going by household income, 55% are below $80k. By net worth, 86% of households are below $850k.
A person in Sudan is averaging around $460 US a year, while in the US it is like $74K, and thus Americans are accumulating wealth at a higher percentage.
Also the comparative lifestyle in regards to goods and services are much different. While it might be more expensive to live in the US the lifestyle is dramatically different. Wealth doesn't always mean accumulation.