I think Trump still runs but Biden beats him by a close margin as perceptions of the economy improve and young/minority voters realize he's really on the ballot again instead of some hypothetical poll question.
Whatever happens, though, you can bet on near-2020 levels of fuckery. Imagine for instance Biden wins by just Nebraska's 2nd congressional district. Or, the true nightmare, he dies before becoming president-elect but after the electoral college votes, and the Republican Congress wants to just elect Trump instead.