The USA has FEIE, (no federal taxes the first $120k/yr), but not all states (like Cali) honor that and may still charge you state income tax.
and FEIE doesn't exempt you from self-employment taxes.
and doesn't exempt non-earned income (dividends, etc.).
Americans can come out ahead (if they earn less than $120k/yr and live in a 0% tax country). But a non-American (like Canadian) doing the samething, would have less restrictions.