Would love to know the approximate ages of those contributing their thoughts to this thread...

I think that in order to answer that question posited, you would need to specifically target such a question to as many trad enthusiasts in their twenties as possible, discover what turned them onto the music, and then figure out a way of reproducing the formula.

As a person in her thirties who enjoys the odd music fest - but isn't specifically attracted to folk clubs - My own take would be that infiltrating non-folk music festivals with good young trad performers would be one possible way forward.