"What this thread about" is the content of an article used to make a point in the OP. To that end, the article headline of "deadliest Pandemic" and the graphic tally of total deaths by some comparative causes is misleading and a poor measure of how deadly a pandemic is to a population.
In fact, in on the continuum of deadlier to deadliest pandemics even the article admits that "it doesn’t mean the coronavirus pandemic is the deadlier of the two: On a per capita basis, the
Spanish flu pandemic killed a much higher percentage of the nation than COVID-19. In 1920, the U.S. population stood at 106 million, compared with 331.5 million in 2020.
And the deadliest pandemic in the Americas was that of smallpox, which killed off 60-90% of the native American population.
By every relevant measure of deadliness to a population the Spanish Flu was far worse than COVID. Unlike COVID, the S.F. was deadly to the very young (<5 yr olds), working age younger adults (20-40), as well as the old (>65). (Note, it killed my great grandmother).
So no, I wouldn't rate COVID as "the deadliest" in American history.