“If you are a police officer don’t go around wearing a UPS uniform.”
Yet, police officers and UPS drivers might wear jeans when not engaged in policing or delivering packages.
Personally, I find my jeans great for when I am painting the living room, mowing the lawn (if one can call my patch of grass a lawn) or changing the oil in the car (ok, I admit, I have no idea how to do that, but if I did, I would wear jeans when doing so), wouldn’t want to ruin any other pants in the closet.