Varients

@Wolfram_EP No. I'm out this it's getting ridiculous.

@schachschachschach Please explain why not. I mean, it's good for children so that they are learning logical thinking, concentration, understanding that opponent has their interest which contradict theirs etc. Also good for adults as a fun time spending. You can claim these advantages for any chess variant, some other board games and even some non-game things. But in general all this stuff with memorizing openings, tactical patterns, pawn structures, endgames, developing theory etc. is a waste of intellectual effort which could be better spent on something more useful to everyday life. It also shares little in common with advantages mentioned above. I dunno what you find ridiculous here.

"The ability to play chess is the sign of a gentleman. The ability to play chess well is the sign of a wasted life." - Paul Morphy

@Wolfram_EP It's a difference saying chess is a waste of time or learning theory is a waste of intellectual effort. I agree with your second statement.