Old guys need to pass the torch for their brands to stay relevant.
It's a selfish act to be 80 whatever with this much political capital and not have been developing protégés with whom to share and support.
Biden should be on a rocking chair sipping a lemonade for the rest of his life at this point, maybe calling in favors as necessary for a 40 or 50-year-old high energy leader who actually has to live in the future he creates.