When you stop to think about it, most heroes are way less effective than regular first responders.

Simple: carrier criminals can shoot their fingernails at mach 5 and dont want the detectability of a gun, and petty criminals lack the connections for illegal weapons. That drug gang crime wave was effectively the same thing as handing out a bunch of guns.

Mustard. Chisaki/Kurono.

And those are the first ones that came to mind. Many villains had quirks more dangerous than a simple gun.