I think it's a bit more nuanced than that.
Just spit balling a bit, what are some advantages the BB offers over the SB...
1. Bigger bores, bore spacing
2. Heads will generally have significantly larger valves that can also work with the bigger bores.
Are there other smaller yet still significant factors favoring the BB? What about lifter angles, pushrod pinches etc?
Are there items favoring the SB?