We have a few underbone bikes available in Mexico, Yamaha's T105 and T110, Honda Wave 100 and several Chinese underbones...
I seriously considered them before getting a scooter, but they have even less power than a 125cc scooter! The scooter also has underseat storage and some of them a flat floor, to me, that gives scooters the edge in practicality. In my opinion, the underbone is "only" superior because of it's ruggedness and big wheels, the former wasn't a priority for a short commute bike, the later was important but not as much as the power advantage of the scooter, so I went with a scooter.
I know there are more powerful underbones in the Asia market, if we got some of them here... I'd have one instead of the scooter.