I suppose another wrinkle is that driverlessness isn't only a cost saving (aspirational or real), it's also a positive attraction eg. for anyone who worries about their safety with a rando taxi driver or Uber guy. There are also cost savings achievable by timeshifting antisocial-hours work to elsewhere in the world, though presumably a significant part of the savings will be simply be the result of outsourcing to lower-wage countries.