I'm 65.
I don't know if pool has become less "popular" with the younger crowd, or if we're seeing a confluence of:
Greater variety in their line of sight.
Pool is less "immediately live & available for consumption" as an entertainment medium. This is definitely a "right now or move on" environment in the electronic world. Increasingly so even across age groups, I think. I seem to feel it more.
More of what "drives" interests among the younger crowd, and rather understandably given today's environment, involves a perception of how it dove-tails into the greater "Social" structure that they aspire to be associated with. Not sure that point has changed all that much among young people across the years... But the explosion in options, and the immediacy of the feedback (along with the personal impact that feedback carries), most certainly has changed in orders of magnitude.
Even if live pool action were to make real headway on TV - and likely it would have to be a streaming medium to survive - Pool would have to find a way to...
#1 - Make the next generation of "entertainees" stand still long enough to notice, and
#2 - Become invested to find an affinity for what they're viewing & a willingness to "share" being involved.
What's new, I guess.