Beauty blenders are fairly new to the world of makeup. We only used to focus on makeup brushes until beauty blenders stole the show. I love using sponges to blend in my concealer and to set my powder. I don’t think brushes really get the job done as good as sponges do. Speaking from my experience, that is.
One main problem with sponges is the dirt and bacteria that accumulates. And washing them can be a little tricky because you can’t scrub with a brush or wash them like clothes.