It's all a mute point, since no matter where you live in the world, a United States citizen has to pay income tax, no matter where his money is, and the income is taxed from wherever it comes.
Unless you renounce citizenship. It happens, but only amongst the super wealthy.
For most people, moving to the third world just to have a few more bucks in your pocket.
It all comes out of your pocket in bribes and the little inconveniences of life like roads, 24/7 electricity, malaria....