Did they though? Seem like a bit like revisionist hang-wringing to me : )
It makes a better story for blame allocation to say that it was a cover up, but you can't cover up something already that widely known.

Yes, it was clear that he had deteriorated from the campaign 4 years earlier, that’s why a majority of Democrats (me included) thought he was “too old” to run (and have a 4 years term) again. But once he declared no other Democrats stepped up to challenge him (well, there was one somebody who, I forget, was unknown then and is unknown now) so the contest came down to “Joe Biden vs Donald Trump”.

Given that choice, we had little choice but to go “OK, it’s Joe Biden. Again. Even though we’re not comfortable with it.”

Then came the debate, and we were all agog at the level of diminution , not just that there was “some.” It took a further week for the public, party elders, and even Hollywood royalty and other supporters to convince him to leave, and by that time there was no opportunity to run primaries or another selection mechanism and the job naturally fell to Kamala.

Yes, it was “widely known”, but I don’t think it was “widely known to the extent that his staff (and wife) knew”, and for that they should not be forgiven.

After the horrendous debate performance, Jill went up to him and said “Congratulations! You answered all the questions!”

Seriously?