America is one of only a handful of grifter nations which charges income tax for citizens based on their worldwide income. The Platinum scheme gives people the benefits of US residency while only taxing on US income.
So a Saudi Royal can live in the US and pay no tax on their billions of dollars income, as long as they aren’t from US businesses. And as most countries only tax you if you’re resident there most of the year, they won’t pay tax anywhere.
Spending 90 days elsewhere is no problem at all for these people. They have private planes, yachts and the French Riviera.