Cordage is one of the most useful tools you can have in the wild and is all but indispensable in a survival situation. It can be used for (among other things) bowstrings, fishing lines, trap triggers, snares, and lashings. If you run out of paracord or don’t have any in the first place, natural cordage can save you a lot of headache.
Most people would likely despair if forced to make their own rope or string. However, the materials needed to do so are plentiful in most places, and the techniques required are actually quite simple to master.