If you multiply the official figure of about 633,00 deaths from COVID-19 by the ratio of actual to expected deaths you obtain 791,250 up to 1,107,750. PNG's estimate is within this range; some experts put the death toll higher at 912,345 The point is that official estimates are under counts. Just how large that under count is can be disputed. Deaths that are directly due to COVID-19 are likely under reported in many locations, particularly in settings where COVID-19 testing is in short supply.
So now know you know why PNG reports a more realistic level of deaths due to COVID-19 in the United States. It is indisputable that the number of COVID-19 deaths exceed the generally accepted estimate of 675,00 US deaths (CDC) due to the H1N1 influenza pandemic of 1918, which is in itself remarkable given the rapid development of effective vaccines against SARS-CoV-2. The Delta variant that has spread rapidly due to low vaccination rates and morbid anti-social behavior will drive the death rate even higher as the virus continues to mutate. It's evolution, baby!
US COVID-19 DEATHS (est.): 860,782