>at one point Taxes in the US were 70-90%.

That figure is highly misleading to cite by itself because the high tax rate also came with a bunch of loopholes and exemptions. That's why despite the drop in the headline rate of 70-90% or whatever, the actual tax take as % of GDP has remained remarkably steady in the past 7 decades.

https://fred.stlouisfed.org/series/FYFRGDA188S

Kind of a false statement; on paper it was higher, but the exemptions were also significantly much bigger and more nakedly biased.

So it's not like it was actually a tax on the wealthiest, more a targeted tool to apply state power.

You could argue that the world is way more globalized today.

you can leave state taxes.

For example GWB "lived" in texas the whole time he worked in washington.