In her favor, (just a suspicion, mind you) that she brings millions in dirty yuan to the campaign.
And in her disfavor, two major dings.
1. Nobody likes or trusts her (even Dems) and
2. She would continually and continuously HOG the spotlight, and try to upstage Biden at every turn. Who wants that?
.
My guess? I would bet a farthing that Biden's minders will select Kamala Harris. (Although ads for our side would write themselves for her, as well.)