What is funny is that nobody ever talks about... successful marriages
Simply because they would find what it takes to be "too boring".
Fact is insuring your survival has nothing to do with "fun". The religion of "fun" is just a product of our modern society, but it wont last. Survival underlies everything, marriage and all other types of alliances/ interactions included. And aint nothing fun about survival. Fun is more a byproduct of being able to survive successfully. Knowing you ll survive better than the competition.
But to put it on a pedestral and classify it as the beginning and end of everything in life is only a trend. In the past you had to work to merit fun , leisures, spare time. Nowadays more and more people access fun without having to deserve it. And for some reasons, more and more people actually "drown" in too much quantities of fun to the point they become...depressed.
Dude who s surviving in a shithole probably feels quantitatively speaking as "happy" as the dude surviving doing his tricks at the top of the pyramid as long as he s part of a stable, hope oriented family/community.