Idk that that's true. Most of the VP candidates on losing tickets don't go on to become president. I found two examples where a losing VP won, Jefferson and Nixon (on a quick ChatGPT inquiry). I admit, this situation is unique since Harris has actually been VP. But being the VP candidate on a losing ticket generally hasn't been helpful.
Kamala ain’t winning no general election on her own.
Michelle Obama said it best when they asked her why she wasn’t running. She said “yall saw what they did to that white woman(hillary) imagine what they would do to me”
America ain’t voting no black woman in for President
Her only chance at be the President is if Joe gets elected and steps down at some point then she gets a chance to prove herself on the Job.
She knows that, which is why she’s out campaigning her ass off for Joe. These people are trying to push out the entire ticket, not just Biden.