All of that rightwing infrastructure existed in 2020, and Biden still got 81 million votes. I don't think it's the lies that matter, having a candidate that isn't tied to the currently very unpopular administration would have made the difference. That candidate also needed to be different from the current administration, and not say something like "I wouldn't do anything different."
Once Biden decided to run again, the Dem leadership backed him and prevented everyone in the party aside from Doug Phillips from challenging it. It was a colossal miscalculation on their part. Probably due to selfishness from those around Biden who wanted to stay in power and influencial positions, and Bidens ego getting the best of him. Having to back out of that position after a disastrous debate performance, and then straddling the line between "not fit to run" and "fit to be President another 6 months" wasn't helping either. Kamala had to convince people that Joe was just fine and very capable as POTUS, but that he wasn't up to the task of another campaign. It's a very disingenuous argument to make, and it hurt her credibility to do so the whole campaign.
The fact is, Kamala never would have won an open Dem primary by herself. She was a convenient fall back plan, that was half baked at best. She never should have been the nominee to begin with, there should have been a primary. It would have told us what we know now, that campaigning primarily on abortion rights, "saving democracy" and the status quo isn't going to win this election.