More than one way to make fire is a plus. A little bulky,
but a spare pair of wool socks has multiple uses.
The cheap "space blankets"---mirror finish mylar sheet.
Not much bigger than a butane lighter, they can be a
shelter, water container, signal or fire reflector. Heck,
you can even use them as a blanket.
What you keep in your kit kind of depends on where
you are. Here on the west side of Oregon, some way to
get and stay dry is toward the top of the list.
Eastern Oregon? Desert Southwest? Water and maybe
warm have higher priorities. There is no "one size fits
all" survival kit.