What is the use of the brushes on sides of escalators?

Question

I bet so many think about what they're for but never remembered to ask. haha

I've always thought they were for cleaning shoes?

Answer 1

They can't have the moving escalator go too close to the wall, or else someone's toe could get stuck in it and torn off.

But they can't just leave an open gap, because then people will drop their pencils, coins, keys, and other stuff down the crack, and it will be a lot of trouble to retrieve.