It depends.
One thing my old man pressed on me is to remember who you are, what you do, and most important, where you're do it. Or you can boil it all down to "It depends."
When I was a young troopie, full of vinegar and sometimes blind youth, I carried a Buck 301 stockman. A 3 and 7/8th knife closed, choice of three blades with three different edges, and enough to get a nice full fist grip on it. That knife took care of 25 years of life for me. I used the heck out of that knife along with the army issue MIL-K-808 knife, AKA the demo knife. Later the demo knife was replaced with a SAK that served well.
Later, in civilian life, as a machinist and father of three, going to Boy Scout, Girl Scout, soccer meets, Lacrosse meets, the smaller Buck 303 cadet worked well for me, combined with the SAK that was always somewhere around. The kids learned to whittle perfect hot dog sticks with it, do some tasks around campsites, and fishing on the river. Again, the small stockman, like the bigger stockman gave a wide choice of blades and edges to choose from for that particular moment.
Much later, after my dad has passed away, his old peanut was sitting on my dresser in a wooden tray, I picked it up and carried it out of a moment of sentiment. Used it a little and was surprised at how well it opened packages, cut twine. By this time the kids were teenagers, my life was a little more settled than in my earlier single days as an active duty soldier. Family man, home in the suburbs, working in the machine shop, some home projects and some gardening out back. Didn't need much knife to cut the jute twine to tie up the tomato and pepper plants to the stakes. Circumstances has changed.
Much later, the kids were grown and out on their own, we were empty nesters and things changed again. Life had gone through changes, and what I carried in my pockets had changed yet again. Dad was right; who I was, what I was, and where I was doing it had changed a few times, and life in my 50's and 60's was vastly different than it had been in my 20's. My perception of the world has changed with my circumstances and life experiences. In my 60's, I found I didn't need what I thought I needed while in my 20's, let alone in my 50's. Just like some guy with a bunch of cows in Wyoming will need what a guy in American suburbia won't. My periodic downsizing of pocket knives was directly affected by what I was doing in my life at that time, and where I was doing it. Just like the mini van I chauffeured the kids around in is long gone now that it's just me, the better half, and the dog. Knives got downsized, cars got downsized, and the house got downsized when we moved to a 55plus community in Texas. And being a retired old fart, I don't even carry much knife anymore. I've always valued small and light weight, and I've only become more obsessed by that as I got older than dirt. Not much knife needed for monofilament fishing line or plastic packages food stuff comes in.
Small jack or bigger knife, it all depends if it works for you, in your particular life and what your doing. Me personally, I tend to go with the one that is the smallest one that will still function at its intended task. Pocket knives, monoculars, pocket pistols, flashlights, whatever. But then I was once the obsessed ultralight backpacker who fretted over ounces, cut off the paper tags from tea bags and trimmed down the toothbrush handle.
