Well TPMS hasn’t been mandatory for over 20 years. But it has been since 08 IIrC. And only for under 10k gvw vehicles. Although I think within the last year it is or will be mandatory for larger vehicles and trailers.
Now many light/med duty vehicles over the last 15 years do have tire pressure monitors motoring but no warnings and thresholds. Like a class C rv
So to your point yes many vehicles have some sort of tire monitoring capabilities whether operable or not. So whatever.
Heck I have only 2 out of 9 vehicles/trailers that even have tpms capability and 1 of the 2 can’t use the TPMS because it’s preset way too high. I actually had to delete the monitor screen from the display to keep from clearing the low pressure warning every time the ignition is cycled.
My point had nothing to do with Tpms anyway though. But good re-direct, albeit wholly inapplicable to the discussion since knowing pressure in no way ensures it’s the right pressure, or even close, in all vehicles like class 2-3-4 trucks and vans.