No one "needs" anything, until they do. And when you do "need" it, chances are, you REALLY NEED IT, especially out in the wilderness.
A two week trip through the wilderness is not a quick trip to the local grocery store, and I don't know what kind of cell phone reception you will get in Algonquin park to call for help if needed. Many unexpected things can happen when we venture out into the wild, and it has nothing to do with whether or not we made any mistakes. Weather can change suddenly and dramatically (weather forecasts are not always accurate), people can get injured from a fall, slipping on a rock, stepping in an unseen gopher hole, getting dumped out of a canoe and hitting rocks, etc, etc. Bottom line, when you are out in the wild there is always the chance you might find yourself in an emergency situation, and you might have no one but yourself to depend on for your survival.
How will you start a fire if everything is wet? Often times wood (tree branches) will be wet on the outside but dry on the inside. How will you access the dry wood without something to split it open?
And what if it becomes necessary to build a temporary shelter because of dropping temperatures, wind, rain? Hypothermia kills quickly. There are no hardware stores around. And you can't count on there being a convenient pile of tree branches around to use for building material. You might need to CHOP some tree branches off.
And of course, a knife can get lost, especially if you get dumped out of your canoe and your knife isn't tethered. Heck, some people on this forum lose their folders in their own homes or vehicles, so it's certainly possible to lose one out in the wilderness. If you are carrying only one knife, and if you should lose that one knife, then you will have NO knife.
Emergency wilderness survival situations are rare, but they do happen, and people don't always survive them. When I used to go camping ("rough" camping, not RV camping), I always brought a certain amount of emergency survival gear, like first aid supplies, fire starting supplies in a waterproof container, pocket flashlights, mini flare gun, signal mirror, water purification tablets, and a few other things (all of which fit in a small pouch on my belt). I also carried more than one knife (two folders, one fixed-blade). A fixed-blade of reasonable size is a very easy thing to carry, even when paddling a canoe.
Like I said, you might not need it, but if you do, you're REALLY going to need it. No one ever plans to experience an emergency survival situation, but I think it's very easy, and prudent, to be somewhat prepared for one.