You listed several states where Biden has no state offices - but did you really ask yourself if maybe there's a good reason why he decided not to have state offices there? Or did you just throw up your hands and assume he just doesn't want to win?
FYI, even though he recently raked in a few million more than Trump did, his financial "war chest" is still significantly smaller than Trump's. So that means he has to *budget* the money, to spend it where its judicious use will result in an electoral victory...and the people who are working with him are in large part the ones who helped President Obama win two terms.
What's more, if he goes out there and makes high-visibility appearances, he would literally be placing his life at risk (he is in the high-risk category, remember) - and it's hard to win a presidential election if one is in the ICU or dead. So he's been doing what he can to send out press releases, to remind people that he really is the only one who can defeat Trump, while at the same time making sure he lives until the day he does precisely that.
And in reality, his biggest advantage is...Trump himself, thanks to Trump's apparent embodiment of the seven deadly sins (and rank stupidity to boot).
So relax, and encourage people to vote...and hope that the GOP hasn't been successful in its efforts to suppress enough Dem votes to win.