That’s there half because it’s a tabletop system and half otherwise there is a break in causality. Just having a random chance of success or failure isn’t very obvious and you don’t see near misses and so on. For most people showing the action is more satisfying.

The underlying system comes from D&D so is full of quite crunchy randomness where results are usually rolled in front of everyone so you get a much more social experience and failure isn’t quite so bad (usually).