And even if you took let's say 95% of their wealth that wouldn't even pay down half of the US debt.
I think all this stuff ends up doing is being a brain drain to make people leave whatever country they're in for other countries
Great, do that! Go start companies in other countries, and trickle down their wealth to employees in the form of wages and salaries.
If only they thought of doing that in the UK! Instead of the rich buying up properties turning them into buy-to-lets, both pricing out working people of their first home, and then taking their income as rent.