I agree with the folks that say this answer is the problem with Biden's candidacy.
Stephanopoulos: "If you stay in, and Trump is elected and everything you're warning about comes to pass, how will you feel in January?"
Biden: "I'll feel, as long as I gave it my all, and I did as good a job as I know I can do, that's what this is about."
This is about saving your country from autocracy. Doing your best isn't enough. Whoever can save it should be the candidate. There is no room for sympathy for an over-the-hill guy who is too proud to admit the truth.