This ignores the cost of sending data wirelessly over cellular networks so remote operators can see the vehicle, the cost of maintaining the software and hardware on the vehicle itself, the cost of maintaining the vehicle fleet, the cost of creating and operating a consumer-facing support system (!!! for Google), the cost of dealing with the enormous amounts of data those vehicles create (even for Google this is not trivial), the cost of maintaining the special HD maps necessary for the vehicles, not to mention the sunk cost of billions spent developing it.

That's not to say you shouldn't dream big (it's a moonshot after all). But there are plenty of reasons to think it won't be viable even if they can solve the technical challenges, and that much still isn't even clear yet.