It's just that we notice it more due to the internet and because modern film sucks so badly. I think people are aware that it's the end of an era. There's no sense that things are continuing with a new generation. Hollywood isn't looking for the next Hal Holbrook it's looking for someone with the last name of Ambutukaluki or Wan-Chan-Xung.
It's the demise of European movie stars from an era when they dominated (no surprise since film and theater as we know it came from Europe). Now the franchise is the star. At least their immortal,. We never have to worry they will not keep making new Batmans. We are stuck with Batman remakes forever.
"Learn from me, if not by my precepts, at least by my example, how dangerous is the acquirement of knowledge and how much happier that man is who believes his native town to be the world, than he who aspires to become greater than his nature will allow." Frankenstein