I use my everyday knife (Fallkniven H1/3G) for everyday tasks like opening, trimming, separating, whittling. What else should one do with a knife? Sort of like asking what the purpose of a pencil is. :P

My DFCG sees much rarer use. I've used it to split firewood, mangle rampant vegetation, and harvest some likely sticks for various things. It's a fun tool, but the sheer size of it limits what it can be used for (and how long you want to carry it). My most frequent use of it is as a trail maintenance tool, and it does this job well.