I have read elsewhere that younger people (the ones who spend $) have little interest in the antiquated Vegas schtick. The Rat-pack days are long gone. Sin City has run its course.
Yes, they are not interested in old-fogey singers and that kind of stuff these days...............
Plus, If I want to gamble, I can drive to my local Indian Reservation about and hour away and gamble all I want then go home...........
I sense that you are exactly right: there is a general shift in taste, away from Las Vegas-style entertainment and resorts, not only among the younger generations, but others as well. What follows will not be necessarily better, but it will be different.
On top of that, the "whales" with the large wads of cash to waste, all prefer to go to Macau these days. It is MUCH more like the Vegas of old, where everything is possible, it isn't mandated to "family friendly" in every way, and the service and attention to detail for the high-rollers is still elite.