It's not good when the United States makes up about 4% of the world's population, but it makes up 19% of the world's COVID-19 cases and 16% of the world's COVID-19 deaths. Some time before the former president left office, the United States made up closer to 25% of the world's COVID-19 deaths.
You talk about some numbers being "meaningless when comparing countries of vastly different size," but you are ignoring that most of these numbers of meaningless when comparing countries of vastly different population densities. Bahrain, Maldives, and Gibraltar are some of the world's most densely populated areas (#6, #9, and #5 respectively), so it makes sense that they are among the top 10 countries with regard to COVID-19 cases per million. The United States is #15 on the list of COVID-19 cases per million, but it's #185 on the list of countries by population density.
You can have some fun with these resources on how the United States, and the former administration, utterly failed in its response to COVID-19. The United States, with a population that is 4% of the world's population, should have made up less than 4% of the world's COVID-19 cases, not significantly more than 4% of the world's COVID-19 cases.
We know there are very specific things the former president could have done to mitigate the effects of COVID-19, but he didn't do them, and we know there are things he did that exacerbated the problem. China and India both have the United States beat when it comes to population and population density, but the United States beats both countries significantly when it comes to COVID-19 cases and COVID-19 cases per million. I'm not sure how it could be more objective than that.