There seems to be no logic in giving someone stuff that they do not want or know how to use. When I gave my kids a few multitools I explained the logic and uses.

I told them to put the multitool in the center console (not the toolbox in the trunk). They should be able to reach the MT while they are in the driver seat. If any of them was in an accident and needed a knife to cut the seatbelt, they can use the knife in the multitool. Or even it can be raining outside the car, or some stray dogs were nearby when I needed a pair of pliers a few years back.

Regarding clutter / declutter.
My car trunk is a dump box. You can find shopping bags, coat hangers, nylon rope, old (spare) shoes, beside the toolbox and cane (in case my knee problem intensifies ). Also there is a "kitchen" bag ( which can help me if I had to eat something, it includes spoon & fork , steel cup, tissue paper ..etc.) So, yes, I am in the clutter camp regarding the trunk, but the seats are reasonably clean and tidy.

With that in mind, I don't have a "survival kit" per se. Stuff is scattered. Fixed knife is in the toolbox with other tools, Fleece blanket is free on its own, Spare socks and other smaller items are gathered in a small old bag, first aid kit is in the glove compartment. And so on. This seems more practical as I needed and used first aid kit a few times but socks were never needed in many years