re: Why were musicians/vocalists so much more talented back in the day ?

Absolutely.
Good, talented rock bands began dying out in the last years of the Eagles.
There were a number of bands I enjoyed listening to in the 1990’s to early 2000’s, but they weren’t (or didn’t sound to be) particularly talented.

I don’t know what’s out there today. Electronic, synthesized, heavily over-recorded stuff? I dunno.
I just listen now to the talented but OLD (like me) 60 & 70 y.o musicians playing in local cover bands.

Is it true about what I heard that Rock&Roll is dead? If so, so be it. It’s societal evolution. But damn, what a run that rock and roll had.