Tax them abroad then. Don't the USA for example require Americans to tax their income even if they live and work abroad?
They could then still live in a place where you can't enforce it, like Dubai. But that effectively results in blocking them from entering your country - and any country you have an extradition treaty with. Because you have an outstanding arrest warrant against them at some point. Plus you can confiscate any assets left behind like companies or real estate.
So at the end of the day, they'll have to decide between a financial cap of (for example) 1 billion or being very limited in traveling. I know what I'd choose.
Surely some will still go for the 'limited travel' option an avoid taxation, but I suppose most rich people don't want to be locked in a country like UAE without any actual benefit (you don't really notice the difference between having 1 billion and 30 billion I suppose, you basically have unlimited money either way).
Yeah, same. What a BS statement above lol