The point being they could eliminate the human drivers and take the whole revenue instead of sharing it.

From ridesharing company PoV right now they are only taking 30%-50% of the revenue, and they have gaps in meeting demand due to resourcing challenges.

The business model is pretty solid if self driving taxis work even if its only in urban and suburbs

I don’t know about Uber but Lyft has a car rental service. Drivers can rent cars from Lyft to drive with Lyft. If the infrastructure is already there, going from “driver turns on an app to accept/reject a ride” to “we accept that automatically” is quite simple.