The US is unique in levying taxes on its nationals wherever they are in the world.
Although you've just made an argument for capital controls. We could call them "dollar export tariffs".
The USA is not unique but member of a very exclusive club. The other member is the enlightened dictatorship of Eritrea. And, IIRC, Trump promised to abolish this taxation during his campaign. I'm not holding my breath.
Believe it or not but there are Americans who relinquish their passport precisely because of this reason. Patriotism is automatically assumed but we live in a globalised world.