Dire? Hmmm. Mostly it cuts salami, cord, occasional tent stakes, & so forth. I've also used it to carve a rough spoon after mine broke, infrequently to clean fish. Note that a razor would not do any of those tasks other than cut cord. None of those situations were dire, but a decent knife made things easier.
Several years ago a friend and I were paddling deep in the BWCA in early spring, and spent most of a day paddling & portaging in 30-ish degree rain. By the time we got to camp we were cold to the bone. All of our critical insulation (ie sleeping bag & spare layers) was safely stashed in dry sacks, & our stoves immediately fired up to get some warm tea down the hatch, but we needed something a little more.
One might argue that need was largely psychological, and indeed that might have been the case. Perhaps we could have just donned our dry stuff & shivered into our sleeping bags. But we were miserably cold.
All potential firewood and tinder was pretty much soaked. A stout knife (4" fixed blade) worked fine for splitting into wet wood to the dry core, and we were able to get a decent fire going. The fire rigged under a tarp, the two of us got out of the freezing rain & warmed up externally, nursed feeling back into our fingers, and cheered up a bit. I was glad to have a few ounces worth of knife, & continue to carry one on all my trips. It's also a good complement to a wood-burning stove...