The Biden/Harris ticket was always designed to lose.
As the D's have accepted and implemented, you certainly don't expend your most valuable candidates in a battle to oust an incumbent President. (Regardless of the vitriol on parade.)
The DNC is more than happy to sit back and allow their old, unlikeable nominees to put their heads in the "political guillotine".
It's much cleaner for them to now have cleared the way for whom they consider to be viable stars of the Democratic Party and potential Presidential candidates; Buttigieg and AOC and Co.
The smartest unfortunately being the criminal Gavin Newsom, who I expect to be the Democratic nominee in 2024.
The Big Guy and Brown's lapdancer will be defeated swiftly by a large electoral victory.
Now, someone please tell me the GOP has future Presidential candidates who have learned to fight like President Donald J. Trump.