Tax liability only matters for people who make tons of money. Further, chances are you are not going to Burma, and rather going to another western country, and in those cases you are going to a country that has a tax treatises/agreements with the US in some form.

FEIE as an example is a deduction that currently goes for around the first ~$120k you earn, you also have your standard deduction. This only applies if you have spent at least 11 months in another country. Then there's housing, foreign tax credit, and so on.

In reality, most expats who earn any sort of income pay $0 to US. The only requirement is that you file every year, like all citizens to the US. Double dipping, like you're alluding to pretty much does not happen much.

Relinquishing citizenship has a fee of $2350 minimum attached to it, which is hefty, but if you're giving up your citizenship, chances are that the bill is paltry compared to your supposed other benefits.