It worked out pretty poorly for the average Iraqi. Hundreds of thousands of Iraqis were killed (some estimates put it at around 1 million), and millions of people became refugees.
Citing the relative GDP per capita number is reductive and doesn’t give a good picture of the average person’s life.
The whole mess led to ISIS and they claim victims in multiple countries.
The GDP should be banned as a metric for being a life quality proxy, it's insane how so many people still refer to it although proven to neglect so many parts of what counts into LQ. To OP: Go check out Doughnut Economics - the book does a good job clearing up economical fallacies & mismodelling of such things.