The subject of "The Purpose of Tires" is not a trivial one. Seemingly, it protects the rim from the pavement, yes? The wheel which is comprised of the rim fitted with at tire. A railroad wheel has a tire which steel ring shrunk on to an iron or steel rim. The tire is formulated to accommodate the surface for adequate grip and adequate longevity. To do so means that they are to allow only one freedom of motion (one directions without resistance) "forward/backward", The other two are not allowed "not passing thru the road surface", and "not sideways"
The most important wheel on the car are the REAR's. (long pause ...................) Yes, the fronts perform important functions of bringing the nose to the direction to go, provide majority of the stopping power, and if a front drive the thrust to fo forward. But, the rears are the most critical in keeping the vehicle progressing in the direction it is pointed. In short, they are the feathers of the arrow, the tail fins of a airplane. without them no amount of steering will not be enough.
Tire tread is only necessary for non-dry road surfaces. The speed at which wet surfaces will lift the tire off the off the surface losing the sideways restriction therefore the directional control, is very low. Minimum legal tread is 2/32" . In my opinion, it should be 4/32". As the tire wears below this the "hydroplaning / aquaplaning" speed decreases dramatically. From new tire wear has a very small reduction in wet pavement adhesion until about 4/32". From there, the continued wear progresses mor rapidly in to a less safe condition. The idea that 2/32" at the time of official inspection for re-registration for one more year is just silly. Better to think that 4/32" down to 2/32" is acceptable. Consider: pass today could not pass the next?
Unsafe tires could work agqainst you in the event of an accident.