This guy has done just fine without a pick:
I was listening to some of his stuff more closely recently. I never really realized what a banjo-like quality his playing has to it. Part of it is from his picking technique, another part is from the hollow bridge-middle quack tone.
Since my hand injury, I can really only play with my thumb and pinky on my right hand. I can do some interesting hybrid double-stops but no real fingerstyle.