In the end, it was the pandemic that cost Trump the election, but probably not for the reasons that you (and he) think. It isn’t because his response was inept, and cost (at a minimum) tens of thousands of lives; America would probably have forgiven him for that if he had truly behaved as a “wartime president.” It was because he told us every day that he didn’t care; his priority was the economy and the stock market, not the lives of the elderly and front line workers.
George W. Bush screwed up the response to Katrina, but what really killed him was the apparent indifference in the photo of him in the airplane flying over the disaster. As I’ve noted before, the public doesn’t necessarily expect you to solve their problems, but they have to know your heart is in the right place. Trump failed that test and justly paid the price for it.