Tire pressure has a massive effect on wear that most people just ignore.
I'd be willing to bet that most people who are having issues with fast PS4S wear on the current gen (21+) Model S's don't watch their pressures. I'd further bet we're going to see a lot of these now, as the temperatures are falling, and tire pressures fall with it!
The TPMS amber dashlight monitor (on any car) protects against "unsafe" tire conditions, NOT optimal conditions! By the time the warning light is set, your pressure is very low compared to nominal. I think it's around 32 or 36, but never tried... But it's extremely easy to see your actual tire pressures through the center display, or even the app. I just think most people don't care.
If you want decent life out of your 21" PS4S's, keep them at 40, always! With correct pressure, and of course correct camber AND TOE (the other thing nobody talks about), I'm expecting even wear and to hit warranty-mileage easily.
I guess time will tell...