The U.S. doesn't have 20% of the deaths in the world. China is lying and Russia is probably lying. That China has under 5,000 total deaths from coronavirus in the land of its origin, and with a population over one billion, is laughable. Other nations are not advanced enough to accurately tabulate deaths, let alone cause of death.
With that said, the U.S. probably does have a higher per capita death rate than many other countries, and the reasons are many. Many have already been addressed. Here's another- the coronavirus is several dozens times likely to kill an elderly person as it is to kill a young person. The median age in Africa is just under 20 years old. The coronavirus doesn't kill a lot of 20 year olds, hence it doesn't kill a lot of Africans. The median age in India is 27 years old. The coronavirus doesn't kill a lot of 27 year olds, hence it doesn't kill a lot of Indians. This goes on and on. Of course, this analysis is not relevant to Western Europe, but, then again, most of Western Europe has a similar death rate from this as does America.
Another reason is that Andrew Cuomo isn't in charge of anyplace in the world, other than New York. Phil Murphy heads New Jersey and nowhere else. Those two, and others, ordered positive nursing home residents returned to nursing homes, creating untold numbers of deaths and that further skews the death rate in America.
In any event, this virus isn't through with anything just yet. Daily numbers show that the U.S. is now accounting for 10% to 15% of the deaths worldwide recently, not 20%, and that will keep dropping as it gradually decreases here and increases elsewhere. Back in March, Italy probably had nearly half of the deaths in the whole world (not counting the ones that China didn't report), and now it's around 3%.
I realize that this information will be lost on the moonbat in Boston- he's a true believer, a fanatic, and, like most virus worshipers, probably on the wrong side of the intellectual Bell Curve.