Could your provide some concrete examples to the above? I'm curious what your line of thinking is.
With regard to 2: I suppose because things related to my hobbies would have no utility outside of their intended purpose. I enjoy weight lifting, but I can't really think of a reason why I would carry weight lifting gloves and barbell collars around. My wife enjoys gardening, and she doesn't carry around anything associated with that.
With regard to 3: I carry combat gauze, a tourniquet, and gloves around with me everywhere I have pants on, which is... everywhere, really. I also carry a flashlight. If I lived in the country, I suspect I'd carry something to start a fire or other survival supplies, but I wouldn't have much use of them where I live.
Self-defense tools are in a category of things that, when needed, you either have them or you die. If I had a family member or child with severe allergies, I'd carry an epipen for instance. But I'm having trouble thinking of many other things that would fit into that category.