I carry one.

The young and foolish try to pack an all singing, all dancing kit into one.

The older and wiser nub it down to a few useful bit's.

I carry in mine:

2 x Wetfire.
3 x Tinderquick.
4 x Wet n Windy's (lifeboat matches to you) with striker.
6 x Waterproof matches with striker.
1 x Sailmakers needle.
10ft heavy duty tread.
20 ft 30lb spyderwire fishing line.
3 hooks.
Button compass.
6 chlorine dioxide tablets.
6 ft sash cord.

I stash knife, mutitool etc in my pockets.