Afraid I' m a bit of a disgrace in this line,Dreaded Thumbpick. I spent a huge percentage of my youth trying desparately hard to play exactly like Merle Travis, Libba Cotton, and John Hurt(those aliens make it very awkward, but I digress). Anyway, I spent years and years attemting to master that stuff, but now I am professional guitarist I'm afraid I invariably play with a flatpick. I'm sorry to be a bad example to the the youth of today, but that's the way it is. Occasionally in the privacy of my own home I play Freight Train, Railroad Bill and other clawhamer classic, but never in public.
   Of the current crop of guitarists(I'm thinking UK folk here) Ian Carr divides his time bewteen fingers and a flatpick(during the same tune sometimes). He was the new whizzkid, but I guess he's just another old fart now.I'm not sure about all the youngsters, but I think you're right, picks are on the ascendant.
In my own case, I put it down to playing in sessions in pubs with accordions and fiddles...it's a volume thing. I invented a flatpick style to match the music going on around me, when I resalised fingers weren't going to do the trick.
People sitting on stools singing "Louis Collins" and playing Anji was the 60's. That was then. This is now!