I hope you are right, but you must know that the "incessant chicken little handwringing" is not going to stop. Wishful thinking won't make it happen. Biden won't be getting any younger. His speech impediment isn't going to get better, nor will his political instincts. I don't think he has dementia, but he is showing the inevitable decline of old age in a super critical job that requires the drive and stamina of a younger mature individual. Neither of these men are really fit for that office, although the bigoted, poorly educated, mendacious, corrupt rapist and fraudster was arguably unsuitable even as a younger man. Half of the public seems willing to give him another shot at destroying our system of government, and Biden is presenting himself as the only one who can stop Trump.
Harris may be uninspiring to you, but, if you think handwringing over Biden's flaws is a bad idea, what makes you think that handwringing over hers is going to help? She has her flaws, but she is better able to present the case for electing Democrats than Joe Biden at this point in time. If you can overlook Biden's flaws and deficits, you can overlook hers.