The whole NFL vs NBA thing in pointless.
NFL will reign king for our adult lifetime.
Maybe, MAYBE, when our kids are full adults then will the NFL fall off.
The NBA has been the best at getting the young audience, I give them that. NFL needs to find a way to do that more, which will be tough with CTE being a more prevalent issue now, but still very doable. My guess is once Goodell finally GTF the NFL will hopefully move towards a more progressive leadership.
But either way, NFL isn't in danger of losing overall popularity to NBA anytime soon. But they still need to be thinking ahead on how will they be able to function 30-40 years from now like the NBA is doing.