Tesla FSD is already being used for on a billion miles per year. Search for "Cumulative miles driven with FSD":
https://digitalassets.tesla.com/tesla-contents/image/upload/...
Usage will continue to grow as it gets better. And it got a lot better over the last months.
And then there is Waymo which proves that with geo-fencing, high resolution maps, additional sensors and remote operators on standby, robotaxis are already possible today. Tesla could add some of these too, if it wants to accelerate meeting regulatory requirements.