I think that unlike the person he's running against, Biden surrounds himself with thoughtful and diplomatic people. Even if he deteriorated to the point that the worst of the Right's propaganda depicted, he would still appear an apparently safer option to me. I don't trust Trump with the launch codes and there's nothing about his temperment or the people he surrounds himself that could convince me he would handle a perilous situation more responsibly.

Biden has his faults, but at least he has some experience in government and semblance of international diplomacy. The free world would be devastated to see Trump return to power, and it's largely just the world's most autocratic countries that want his return. The danger he poses trivialize the minor inconveniences of having a responsible leader fumble his words occasionally (or even frequently).