As for Trump, with all the leaks and tell-all books there have been, I'm sure there's people with even worse material on him waiting to drop it as an October surprise.
If they plan to time it that way to try to affect the election, they're ignorant of the situation we're facing and how it got this way.
A brief summary of the politics-watching life of a Republican/conservative or even a resident of a mostly Republican/conservative area...
•Turn on a TV news show/channel that isn't Fox: watch them fling a bunch of false accusations about what horrible monsters you and almost everybody you know are, along with famous Republicans you don't personally know.
•Read an article about politics online or in a newspaper: watch them fling a bunch of false accusations about what horrible monsters you and almost everybody you know are, along with famous Republicans you don't personally know.
•Listen to or read speeches by famous Democrats: more of the same
•Meet a Democrat or political lefty in person who wants to talk about politics: get yelled at with false accusations about what horrible monsters you and everybody you know are, try to reason with them, just get interrupted with more of the same because they're not listening because they're too anxious to tell you more about what you supposedly think according to them instead of hearing anything you actually think.
•Go online to forums or chatrooms or Twitter or whatever, any that aren't set up by and for Republican/conservative members: get treated to more of the same kind of behavior as the in-person one except that it's technically impossible to interrupt you but they still pay just as little attention to anything you say as an interrupter anyway because they're all too busy writing their next post to tell you how what they magically know you
really think is something completely different from what you already told them you think, and there are lots more of them than you could meet in person so there's also the benefit of the "getting ganged up on" effect and watching them high-five each other over how much dishonesty & rabidness they manage to pack in per post.
•Try to just stay out of all of that and live & let live: still get reminded of it periodically by in-your-face types trying to pick fights and infuse politics into everything else in life anyway, including in "entertainment" TV & movies that still always manage to present your kind of people as the stereotype that all the Democrat/lefty hate-speech claims you are no matter how non-political the subject might originally have been.
There's not a lot of point in tossing one more attack onto the pile for an audience that's already used to the fact that the other side is always coming up with more & more false accusations & other lies. It's what they've been surrounded by for years, often essentially their whole lives. That's the framework through which any new ones added now will be interpreted. They already know not to believe the next one before it even happens, because political life is always just more of the same over & over again.
It appears Americans in particular tend to get shocked by a little touchiness, or like to pretend to be shocked by it.
I wonder if Trump's own history is a large part of why the "creepy uncle Joe" angle failed.
Everything about Trump is always why anything against Biden fails, with help from the "ELECTABLE!!!" mantra.
But, aside from that, creepiness works pretty differently for adults and children. In adults, it's always assumed to be sexual, but in children there's a dichotomy. Then, sexual becomes much worse, but, as long as it's not sexual, it's not an issue at all to a lot of people because a lot of people, at least
non-sexually, think it's just fine to act like you,
non-sexually, own children's bodies. They're not generally acknowledged to have the right to refuse hugs, shoulder-grabs, head-pats, hair-strokes, pinches, lap-sitting, & so on until they get old enough for the automatic universal sexual element to apply. (And the people who are the most prone to see it this way are the very old, which are Biden's personal base.)
So, what has Biden done that either was unmistakably sexual, or involved old enough targets to be out of the "it's OK to do any non-sexual thing you want to them" age range? There was something at an event he wasn't even at, and the rape thing that fizzled away, but that's all that anybody seems to remember. I've seen one case where he gave a woman the classic stroke-her-lower-jaw-toward-her-chin move, which says "I'm about to kiss you so I'm putting your face in kissing position", but somehow that's remained very obscure. I've only seen it once and I've never seen anybody else act at all aware of its existence. And anything that people don't know about, no matter how horrific it is, can't affect people's behavior. So that just leaves only the stuff that people do know about, which is just stuff that our culture treats as OK for really really old people (especially relatives, followed by famous people such as politicians) to do to children.