Maybe 'overkill' but I don't see 'ineffective'....chopping holes in ice, prying, chopping branches, splitting wood, digging holes in the dirt and many other bushcraft tasks are easier with a large blade.
Not sure how we're defining "big" but I will say this, I never carried a fixed blade until I became and ETSer, and even then it took time convince me that I need one. I always carry a a folder/multi-tool, but now I also carry a 4 - 5 incher when I'm in the bush. Bryd speaks the truth. They're just so versatile. I don't chop logs with mine, but I do use it to pry, dig, chop through ice, split branches to get dry kindling, etc.