Like a cat, there appears to be much more than one life to it. The “and roll” part is often considered superfluous language today. It’s just called rock, or rawk if it is particularly rawkous.
That is true to an extent. Someone once said (Muddy Waters??) that Rock needs a kick start with Blues and that has occurred from time to time - SRV, Lynyrd....
Sears did the same thing to Roebuck. Roebuck’s is opening a new store with Roll, though and they’re calling it Roebuck and Roll. (George Carlin bit)
I enjoy listening to the old records, but the Beach Boys singing "California Girls" or "Fun, Fun, Fun" is a little creepy when they're in their sixties.
What you're seeing today with music is the same thing you're seeing with late night talk shows. In the sixties, there were only a few outlets, so a few people could push an act until it became imbedded in the public consciousness. Today, there are so many outlets that it's practically impossible for a single band or singer to dominate as someone like Elvis did. AM radio just can't blast the same song out over and over until everyone has it wormed into their ears.