I think no player ever did get the Banjo off like Earl or for that matter Unlce Dave. Scruggs and Macon were great friends ... long before the ummm errrr Blue Grass.
Nowadays if you'd like to find some stimulating Original Banjo look no further than Clawhammer, lots of inovation, seen a few guys playing Civil War style Instruments with 6 strings. Very nice music.
Uppicking is still there of course and there are lots of Tunes not in the Bluegrass Style. That and the CH revival is making what is a great folk instrument real popular again, BTW who has heard George Gibson ( Kentucky )?
Don't know what the origin of Blugrass is but I do know there are a lot of folk playing it. Seems to me the 'timing' of the notes is real clear on the Banjo but may sound a little weak on the Spagetolin or Fuddle.