I think it is you who needs to school the rest of us as it is your side that is always trying to force the issue and initiating threads like this.
if you read my response to Any Cal you will see that I wrote that if you are proficient with your tool that is all that matters regardless of size.
But to answer your question here goes:
In heavy woods my big knife can do anything your little knife can, that is necessary.
My big knife can make short work of building a shelter your little knife cannot.
More cutting edge means longer lasting edge.
In thick bush or brush I can wack my way through and have done so many times, you cannot.
I can use it to dig better if need be.
I can use it to turn over rocks keeping my hands away from possible danger under a rock. Stick will work if available, but don't have to count on it.
fire wood reasons same as shelter
Defense, knives are like teeth and the bigger ones tend to make a better impression on predators 2 legged or 4. Fact, as I have experienced this.
There is much more, but just off the cuff that is it.
Durability is another one. Big thick knives tend to be much more durable than a small knife, obviously. There are notable exceptions to that rule as in the Becker Campanion and certain Busse knives and others in that style, but I consider those small big knives as they are built like a big knife and carry the heft of one.
I have several packs. I have very light day pack in which I carry a big knife and a leatherman plus several other necessary items. When I go extended I take those tools with me an also take along a pocket chain saw and hatchet or khkuri if needed. But if I need to save weight, my big blade always goes.
your turn......