"What they call rock today is just not the same"
Of course not. Should it be? What you think of as the classic rock sound is different from what your parents or perhaps older siblings would have thought of as rock music.
"There will never be another RUSH, ACDC, Neil Young, Crosby, Stills and Nash Beatles, etc..."
And in the heyday of these bands already there were those saying that there will never be another Chuck Berry, Eddie Condon, Jerry Lee Lewis, Bill Haley etc.
Heck, listen to a band such as the Who from their first through their last albums. Rock wasn't even the same from the beginning of their career to the end.