Aw man, I live about a half mile from from a MLKJR Blvd, regularly hike remote trails, and my work takes me to questionable places. I'm screwed lol. I also spend time at boat landings which tend to be great ambush points and bad stuff happens at those. Was at a remote boat landing once and a guy ran out of the woods and showed me his knife demanding to let him in my car. I let him. Literally stood maybe twenty feet away watching him rifle through the bunch of nothing valuable in there until he finally ran back into the woods with nothing. Idiot. I had a pistol on me, but he never had to know it since he kindly gave me room to move away from the car and didn't try to hurt me. Happy ending for both of us. Hiking trails, I'll usually have my big pointy eared dog as well as being armed, along with a muzzle so the dog can't bite emergency personell in case I get injured. Same with going to questionable job sites.
Self defense may not be necessary, but I think it's prudent for some people like myself that spend time in areas where ambush especially is a real possibility and does happen. Not talking about getting in a fight, but straight up criminal ambush. I really don't want to have to use a weapon if at all possible. Martial arts can provide another option in your layers of preparedness. If you have family that depends on you there's kind of an obligation to make it home alive so more options is better!