Lol Tesla has made significant progress and doesn't show much sign of slowing down. There's no reason to think there approach can't work at this point. People go weeks without intervention.
https://www.teslafsdtracker.com puts miles to disengagement at 30 and miles to critical disengagement at 300 for all v12.x.y versions. Note: this is crowdsourced data and the users themselves get to decide what's critical and what's not.
As far as numbers required to make it fully self driving, it's at least 3 orders of magnitude worse than the big players. Waymo and Cruise routinely had 30,000+ miles per disengagement during their California testing. That's one disengagement for roughly 3 years of driving.
On top of all that, Waymo does intensive 3d mapping for their service locations. These maps have to be maintained. Then the cars need sensors that take advantage of those 3D maps. If that combination of intensive mapping and LIDAR sensing turns out to be necessary to get beyond FSD's current and near future performance, then Tesla isn't even at the starting line.
Well, being as how people get to pick and choose when they use it, and that the driver has to remain vigilant at all times, I'm not surprised.
But this is easy to test: stick random people in the car and go to random locations with FSD, see how it works. Why haven't they demonstrated this yet?
I am very skeptical of the "weeks without intervention". It's cool technology, but I never had a single trip where I didn't need to intervene at least once.
It would regularly blow through school zones, failing to read the posted sign.
On a couple of occasions it veered off the road on to the shoulder.
My thinking is the car will never be level 4. It doesn't have sufficient sensors or NN compute power.