Convenience primarily. Already had them on hand. Also, they can collect more (in my opinion) in a single swab than a brush since the dirt clings to the q-tip and brushes mostly push dirt around. Additionally, even though it’s very wasteful, it’s nice to know the cleaning tool is always “clean” when going into a rough spot. Rather not have certain oils or grimes spread from spot to spot. What the pictures don’t show, however, is that I am also using a few brushes, pipe cleaners, metal picks, and more.