Generally not a fan of geohot, but this is pretty possible, especially once self driving tech becomes available through suppliers like mobile eye / Bosch/ continental etc. (it’s possible it will stay a Tesla / Waymo duopoly but I doubt it)
The chinese already run self driving taxis in ~20 cities, more then Waymo and certainly outpacing Teslas. The Duopoly ship sailed.
The problem with Waymo is simple: at the price they're doing it, it isn't worth doing. Waymo only works with real drivers ready to take over at the first sign of trouble, so it's at best level 3 self driving, definitely not level 4. This may compare favorably with Tesla's taxis who failed level 3 self-driving and proved to be unsafe at level 2, which really is failing level 2 if we're honest.
I mean, Musk SCREAMs in the news they're improving, but let's not forget this is the same Musk that promised level 5 self-driving by 2016 (2014 if you count ...). And if you can tell: yes, I'm still pissed about believing him enough to pay for that.
Also Waymo is cash positive per car, and more expensive then human drivers - they accidentally unlocked a premium market where people are happy to pay extra to not deal with other humans. At their price point its certainly worth doing the robotaxi business