I'm still waiting to hear examples of Stephanie advocating for athletes. Or examples of how she is more "new era" than Bob other than her age. Bob clearly has superior skills...
A big thing that hasn't been mentioned much is that Bob's age works in his favor. He is retired (as far as I know) and has the time to travel all over the world for these various committees he is on currently and has volunteered on in the past. Yet he has ample energy and has certainly kept up with technology.
Stephanie works full-time. I'm not going to pretend I know much about her personal life or finances, but I would be surprised if she were in a position where she could quit her job to focus full-time on this volunteer position.
A big reason Bob gained as much support within the IAAF as he has is because he has spent many years putting in the hard work required to get there. This idea that Stephanie can just waltz in and immediately rise to the top is insane, and knowing her personality, it just doesn't seem likely. She can be very charismatic and will certainly win support in a few places, but the IAAF is very broad and diverse, and her strong personality, and the backstabbing route she took to get there, will likely turn off many delegates, especially those who like Bob.