You’re making a lot of blanket statements here. What should she have addressed that she didn’t?
It's very simple.
People fukking hated Biden. They did. You can say it's fair, it's not fair, whatever. But they hated him.
She should have immediately and forcefully broke from Biden in every conceivable way. She utterly failed to do that, and Trump successfully made this campaign a referendum on Biden. That was her fault for letting him do that.
So how could she have forcefully broken from Biden?
1. Blatantly say that the economy is not working for normal Americans. Throw Bidenomics totally in the dumpster, something she didn't do until too late. And, more importantly, propose real, concrete solutions. Say that day 1, we will put price caps on all groceries and gas. Demonize corporations. Blame them for all of it. Don't even engage with immigration rhetoric.
Say that there will be a rent freeze. Say that there will be federally mandated homebuilding. Stop talking about fukking small businesses. Emphasize price gouging more (this was actually good messaging). Make the campaign about what she will do for the economy.
Talk to young men on this issue as well. Tell them that corporations and oligarchs are the reason they aren't as successful as their fathers and grandfathers. Tell them that only through attacking these structures will they get the American dream they were promised. Cut into Trump's messaging.
Now, could she actually implement all of those policies? Probably not. But it would have given her a chance to win. Trump says shyt he can't and won't do all the time. It works, Americans are stupid.
2. Another way to leave Biden in the dustbin would've been to break with him on Gaza. Not to go full Free Palestine, but breaking with him forcefully would have built credibility on her foreign policy chops among average voters who may not even care about Gaza. Just taking a forceful stance and not blindly following Biden's objectively catastrophic foreign policy blunders in ANY direction would have helped. Obviously I would have liked her to go the leftward direction, and I think it would have helped her with the base and hurt her with no one who wasn't already voting for Trump.
Anyone offended by breaking from Biden is a party loyalist and would vote for her anyway. Doing so would have given her credibility among the younger, low propensity voters and Latinos that showed out.