Is Chess a waste of time for non-pros?

no

There's a certain draw to the idea of memorizing full games but then you realize that most games have a lot of "noise" to them past a certain point, and even if you remember the moves what's the point if you can't really remember the point of the moves and the alternatives. Carlsen may remember 10,000 games but I bet he remembers 10 million opening or endgame scenarios or "points" of note. Learning a game to Carlsen is like learning a name to the rest of us - ok make it an exotic name and both the first and last name - let's not exaggerate. Careful inspection for a little while is all he needs for it.

Bottom line: If the purpose of life is to enjoy oneself here, then chess isn't a waste of time for anyone to whom it's pleasurable, no matter it's their career or not. And if you believe in an eternal nirvanic afterlife, then everything that doesn't further that goal is a total waste of time, since we're all doomed to die one day anyway.

You cannot dispute whether or not one enjoys it since you obviously don't know, and I also deem it a complete waste of time arguing whether or not it advances one's religious objectives.