Well, actually most of that stuff looks useful to me (to store in the car). Some of the things I always take hiking are stored in my car when I'm not hiking (compass, whistle, water bottle, headlamp, etc.) and while I never really thought about it I'd sure use that stuff if I got stuck somewhere or needed help getting out.
I have a small water filter I bring along on hikes depending on my travels. Often it isn't needed for higher elevations oe very remote terrain where the risk of giradia is nil.
Many times I go out solo, which I'm sure doesn't thrill my wife much. Regardless, she doesn't complain and she knows I am ultra conservative when I am hiking off trail in remote high Sierra locations. The evidence of my conservatism shows up when I often do not get to my intended destination - mostly when common sense outweighs my desire to get to a mountain top (when others are along an ego can cause one to travel to places you really shouldn't be).
I think the Kim tragedy is the result of time and peer pressure (wife/kids/friends expectations) which eroded his common sense away until it was too late. If he had stayed with the car and had some of those gadgets, he'd be giving us a good review of what to take on a road trip gone awry.
The worst experience I've had, minor compared to most, was simply getting w-a-y too cold when camping at about 11,000' one night. My shaking was uncontrollable no matter what I did. I was about 16 miles from the trailhead, so I just packed up and started walking out. An hour and a half later I was sufficiently warmed up and I was back in town for a hot meal by noon.