Like another poster said earlier in this thread, brushes can counter short range shooters. If you look at the top of the meta picks in competitive tournaments right now you'll see a ton of them. Splattershot, Zap, Splash ect, take your pick. For example, if a Painbrush gets the drop on a .52 gal, it can utterly demolish it in short order. I also said earlier that brushes needed buffs in general to their ink consumption. Yes they can be annoying, but they don't have a ton of range.
Even the Painbrush only has about as much range as a short range shooter. Like rollers, brushes need to get close in order to get splats but unlike them they don't have the advantage of either a 1 shot or a vertical flick. As a matter of fact, brushes are the only melee class not to have a 1 shot. They can't charge their swings like Splatanas can and they have severe fall-off damage. On top of that, a big reason for all the buffs to their ink consumption is because brushes, pardon the pun, need to paint. They may be mobile as all get out, but they still need friendly ink in order to shark and set up shop. Every single roller is more ink efficient while rolling than brushes are while sliding. In conclusion, brushes aren't the best class by a long shot, but they needed all these buffs to get to mid tier at best. Any nerfs now would be catastrophic for them.