Biden really doesn't want to be President. Like most 78 year olds he's focused on family, faith, winding up one's affairs. He never had any kind of political vision. He has always placed himself comfortably in what used to be the middle consensus of the Democratic Party. He never took unconventional or innovative positions.. certainly not courageous or righteous (from any kind of set personal moral principles) ones.
He's now in a position where the political centre of the Party is drifting leftwards, especially with respect to the post structural Culture of Death (feminism, abortion, homosexuality, euthanasia, ethnic and racial tribalism). It's drifted far from the political centre of the US electorate. He'll try to keep up but it will lack any kind of authenticity.
My sense is he'll be out of the Race by the 3rd or 4th Primary. My guess is Kamala Harris will win the nomination because she embodies what the Party now stands for. She is the Anti-Trump. Sanders will likely come in second but the Party is far too radically, racially and, culturally ideological now to accept a old style Social Democrat. And Sanders is the one candidate who could give Trump and race in the Rust Belt.
Trump will win the 2020 election because the Dems will have locked themselves into an ideological ghetto, and, will have left the American heartland far behind.