[usrusr]

Roaming between "regional ubers" might be such a thing, where the day to day business runs centrally within each regional system, but profile access and payment forwarding for roaming is "cryptoed". I don't really see why that would absolutely need a full blockchain though, as there are only so many things you could meaningfully cosign with three parties involved (assuming drivers don't roam). Bbut maybe I missed something that would need getting written into a public blockchain, maybe for establishing the required trust network between providers.

But this would have to come into existence with all the lack of glamour as any dry old industry standard, the whole scenario contains absolutely no room for a starry-eyed "Uber on blockchain!" startup (which are doubtlessly legion).