BI does 2400 min damage. That's pretty significant. Also the BI link is much easier to do since it requires specific setups that are much easier than 236236C link after air combo (and often 236236C combos from the ground are weak in general)
No BI combos are "optimal" in the sense that they require either charge 5B corner hit, OMB, or 25 meter to set up and an additional 50 meter for the super itself. Oh and the awakening requirement doesn't help.
TBH: I've never used a BI combo in any match. Getting awakening AND red axe is kind of ridiculous. Usually when I have red axe, they die before i can finish the combo should I go into awakening. Usually when I'm in awakening, I'm in green axe and can't afford the reset after getting red axe.