> By which metrics has Tesla been left in the dust wrt autonomous driving

By the fact that they don't have autonomous driving. And this very judgement demonstrates that.

If you have to keep your full attention on the road at all times and constantly look out for the 10% case where the autopilot may spectacularly fail, it instantly turns off the vast majority of prospective users.

Funny enough the tech that Musk's tweets and the Tesla hype machine has been promising for the last decade is actually on the streets today. It's just being rolled out by Waymo.