The US isn't a benevolent force for good, it's pure old capitalistic greed and realpolitik. That lots of good has happened thanks to it is mostly accidental.
Anyway the world is not black and white and there is a lot of nuance, however the US was still probably the most benevolent “hegemonic” power that has ever existed in human history (especially relative to its power projection capabilities)
Most estimates of Iraq war casualties are in 100-600 thousand range. The one estimate putting it at 1 million is an opinion poll. There are no estimates beyond 1 mil.
But if you judge by body count, you have great examples of actual millions dead like holodomor instrumented by stalin (3+ millions of Ukrainians), Chinese famine due to mao policies (10+ millions), khmer rouge massacres (average estimate around 2 mil), etc. Something is common among them huh?
US is not a saint and everyone makes mistakes but it is thanks to its influence and role in global economy we have drastically less death.