The number of Americans who died during would include domestic deaths due to old age, illness, accident, etc. I think you mean the number of Americans killed in WWII, and even then his number is incorrect. See https://www.nationalww2museum.org/students-teachers/student-resources/research-starters/research-starters-worldwide-deaths-world-war, which shows the number of Americans killed as 418,500 (and the number of killed in military service as 416,800). He simply is incorrect in what he said and also incorrect in what people are guessing that he meant.
I agree that the majority of deaths from COVID-19 are among those age 55 and above, but thats cold comfort, and many who die do not have comorbidities. Moreover, it is becoming increasingly clear that many who survive suffer damage (e.g., to the cardiovascular system) that may well be permanent. Update: Here’s a report that indicates that survivors of Covid-19 may also suffer cognitive damage: https://www.sciencedaily.com/releases/2020/12/201217154046.htm /update
I think we can agree that the US response to the pandemic was extremely poorly handled, and it has not improved all that much. The vaccine distribution “plan” was poorly thought out, and now we find that many vaccine doses are missing. The overall US response to the pandemic has been a debacle brought about by incompetence compounded with ignorance, taking tens if not hundreds of thousands of lives needlessly.