If Biden slow walks his decision to run, it paralyzes all other potential candidates-except Harris. If Biden thinks she’s been loyal and wants her to be the nominee if he doesn’t run, she has a huge advantage because Biden can hand over his political organization and operation as an incumbent, overnight.
Tactically you very well may be correct. Choosing her in the first place was a tactical, political decision that may or may not have helped the ticket (I actually don't think it mattered). I just don't think she's got the heft to head the ticket. BICBW.