It works "at scale" if you have no idea what "at scale" actually means and have never left the Bay Area or NYC. Or if you like, don't believe weather exists.
I ride in my friends Model Y Performance with HW 4.5 from time to time and it always gets us from point A to point B without any interventions that I have seen yet and this is in Wisconsin, and yes it was working well with some snow and ice conditions this past winter. It seems really impressive to me at least.
Okay, but do you admit it (self-driving, either Tesla or Waymo) works in the Bay Area? Because the OP said self-driving is not remotely working "at any scale".