I like small fixed blades. But I carry small pocket knives. Yes, a pocket knife can do most anything a small fixed blade c an do without the out and out abuse al la Cold Steel videos. I've used small folders for fish and game, and hard work on construction sites.
But...
There are two areas that the small sheath knife excels in. One is convenience. Take it out, use it, put it back. No question of opening or closing, or of it closing before you want it to. I like a small sheath knife when it's really cold, or wet, and my old arthritic fingers are not as limber as they use to be. The other is comfort. The handle of a folder is made around the holding the blade. The sheath knife has no such mandate. You can shape a sheath knife handle any way you want it. Especially if you have a narrow tang knife. I have two small pocket size puuko sheath knives, and they are the most comfortable small knives I have. The handles are contoured like no pocket or folding knife can be.
Of course, rinsing fish guts or deer blood is way better with a sheath knife than a folder with all the nooks and cranies for germs to breed in.
Then there is the question of safety. Age, wear and tear, evan all affect a folder. Locks can develop play, dirt can sabotage the integrity of the lock. Not to mention that when you leave your house in the morning, you never know what fate has in store for you in the course of that day. You may find yourself in a position where you just may have to abuse your knife to pry a bit. You never know.
I love my pocket knives, but I'm a product of my environment. Due to this mostly anglo-saxon society we find ourselves in here in the U.S., people frown on a sheath knife hanging of your belt. I envy our Scandinavian cousins, who go for the puuko in such a way, that pocket knives are not the main stream in some countries. If a large puuko is too big for city use, then they carry a small puuko in a pocket. Much more logical tony mind. But unfortunately for me, I live in the peoples republic of Maryland, where in addition to stifling gun laws, we have some insane knife laws.
While I would give away all my pocket knives to carry a small puuko all the time, in our little peoples republic, it's illegal to conceal any sheath knife. Yet, Maryland considers any folding knife a 'pen knife' and there is no limit on size. So while I can have a number 12 Opinel bulging in my pocket, A tiny Buck Hartsook around my neck if concealed by a jacket, is way illegal. You can have a 6 inch bladed folder and it's okay, but have a 2 inch sheath knife in a pocket and you go to jail. I'd love to know what the state assembly was drinking when they set that up. So I'd I have a sheath knife version of my little Case peanut made up to carry in a pants pocket, I'm going to get arrested. Nuts.
Arguing that a one piece of metal tool is not any better than a two piece tool hinged in the middle, is nuts as well.
Carl.