In all reality, I think everything but a knife and maybe some cordage could be considered non-essential. You can pretty much accomplish just about anything else (depending on your AO) with natural resources. Sure, I can start a fire with sticks, I can make a bow and arrow, kill an animal, tan the bladder/stomach for a water container and use the hide for shelter. I've done the whole primitive thing before, and while educational, it's not something I would want to do day in and day out. Survival is really more than just surviving, more than scraping out a living, its about making a life. We just understand the need to adapt that life to a different set of curcumstances, and its the items in our bags that makes the adaptation process a little smoother.
I pack a lot of non-essential crap for sure, but man, baby wipes can be worth their weight in gold at the end of a LONG day.