Performing live and putting an album out are two different things


There are many artists who out on a great show but their work in the studio is average conversely there are many who put in great performance in a studio but cant do it live

Also comparing people 20years ago to now is a bit harsh. People have kids families partners and have different interests as they age.

Some of those performers you slate as not being as good now more than likely not have the motivation to go out night after night and conquer the world. They have done it and would rather kick back counting their millions doing other things most of the time