I saw an interview with Bowie from back in the 90's where he said he'd probably would've wanted to be a tech entrepreneur more than a rock star had he been a teenager then. It's probably true that young people eager to make a cultural mark are more likely to gravitate to other fields than music at this point.
It's diminishing rap a bit to say it 'holds a strong influence on African-Americans' - Kanye, Kendrick, Death Grips, Danny Brown etc are huge with the Pitchfork crowd these days.
Far as I can tell young people are still enthused about music, but growing up with streaming is different to growing up forming record collections I should think. But there's a music-obsessed guy in his early 20's at my work who's basically into the same stuff as us elderly Music Babble types so who knows.