You're correct. But consider that perhaps the VP and members of the cabinet (who seem to also have some responsibility in raising this kind of issue) didn't see a reason for concern. Yes, perhaps she and the rest of the cabinet should tell us about this.

Though I have no problem with Biden stepping aside in favor of Harris, I think the post-debate reaction against Biden has been overblown. It simply magnified a problem a lot of people had, that (to them, at least) Biden is too old to do this another four years. There may very well have been no "there" there.