I met a Italian man at immigration control in Ethiopia, at the Addis Ababa airport, he had been traveling Africa and this was his third attempt to enter Ethiopia. The first two attempts were via land borders with Kenya and he had been turned around both times, despite having a visa, because border control felt it would be too dangerous for a white man to travel through southern Ethiopia at the time. So he had to travel to Nairobi and get a flight; he was admitted this time, but he had to pay for another visa at the airport. Unclear why? He wasn’t best pleased about the whole thing.
It's the reason nearly all US citizens who move overseas eventually give up their citizenship. My great aunt left for Poland 30 years ago, and renounced her citizenship within 3 years because she was paying taxes on everything she earned twice, one under Polish law and again under US law.
And US isn't alone nation in this.
That’s how I understand it, anyway. I hope to be corrected if I’m inaccurate as this is not my area of expertise.