Miscellaneous. I usually check tread depth on new tires so I can judge the wear myself later on. On caution though you have to read the proper scale on the device.
I don’t have a brother but back about 1965 my brother in law was driving his 61 merc down the road and saw one of his four wheels bouncing in the ditch. Bearing wear ignored but at least he could recover the wheel. Of course bearing are different now but they still serve the same purpose.