I don't dislike Kamala, and Trump is a sociopath. I realize Joe Biden probably had cancer before he dropped out and that's why he dropped out. But I have to also say that voters probably didn't like the bait and switch approach where they suddenly felt they had to support her simply because she appeared as the candidate in the last legs of the campaign. I think diversity and female leadership is important, but probably asking undecided voters to go for a POC woman when that's not who they started out supporting probably didn't help. Old white centrists don't like that, and she didn't have time to build a campaign and show her skills like Obama did. Probably a good chunk of people straddling the line vote wise didn't love that. We had this happen in Canada recently with our new prime minister Carney, but he's an older white centrist dude, and we were clearly ok to hold our noses and do it to keep out the conservatives, but I think if it was someone like Kamala they might not have won.
Biden didn't drop out because of his cancer. He dropped out because that disastrous debate made it impossible for him to win. If he had really wanted to drop for his health, he would have done it at least the year before to give time for a primary.
Even without the debate, Bidens poll numbers for years before the debate made it impossible for him to win. No candidate has ever come from that far behind and won. When Roe went down on his watch his numbers cratered and never recovered. The DNC knew this but they wanted their AIPAC war to continue uninterrupted, or else give the chair to trump, who was their desired pick anyway. So they bought that outcome.