When you complain about the US they tell you "if you don't like it you can leave" but the USA is one of only three countries that taxes non-resident citizens on non-resident income (the others are Eritrea and North Korea) so it turns out you can never really leave.
Also if you renounce your citizenship you're taxed at 20% on all your assets AND if a determination is made that you renounced in order to avoid future taxation YOU ARE DENIED RE-ENTRY TO THE COUNTRY.
Many Europeans are under the delusion that the USA has a very friendly tax regime but the reality is far uglier. US citizens are truly slaves owned by the government.
The taxes are deceptive, too: sure you pay less in federal income tax than in most places. Now you have to pay either state income tax or property tax and buy expensive health insurance. Now you're probably back on par with your home country.
"oh but property tax can't be that bad" lol I had a 1800sf (167sqm) suburban house, 2bed 2ba w/garage & I paid OVER $600/MO in property tax on a *teardown property* (meaning, when I sold, the condition of the house had no residual value and was torn down & a new house built).
around $8000K annually to the city to effectively rent a house I already owned outright - and that's a tax you pay unless you're so poor you can qualify for an exemption, so: a very regressive tax (this wasn't a second property or investment home but my only home, the one I lived in)
and then when you understand how property tax in many/most places is used as a means of keeping the schools in white neighborhoods well-funded while denying resources to schools in Black neighborhoods it gets even uglier