I looked at waymo.com and the only city anyone can take a ride is Pheonix, I didn't realize it's still not generally available in SF or LA (or Austin). Though I

I looked at waymo.com and the only city anyone can take a ride is Pheonix, I didn't realize it's still not generally available in SF or LA (or Austin). Though I know it can do all these things now, why they don't open it to the public?