In nearly 50 years of backpacking, I don't remember a single instance where a knife was absolutely needed. Even cutting cord can be done with a match/lighter. That all being said, I do carry that little 0.7 ounce swiss thing, and always will. But a screwdriver or pliers???? Never ever needed in any form. Sorry. Tweezers, mini-pick, mini-scissors and mini-knife all on the 0.7 oz swiss army knife has you completely covered.

BTW: I do subscribe to the 10 essential thing completely, but my interpretation thereof deems the swiss knife adequate. Fuzz stick? Back in the 60's in boy scouts maybe, but now I carry trioxane fire starters for emergency fires. Much quicker and works every time. Yeah, another 1.25 ounces to carry, but these puppies work so well.

I also carry a larger folding knife when I technical climb with ropes, And a leatherman when skiing, for reasons Mags stated, but not applicable here.