There is a man-versus-nature story: drain swamps, irrigate deserts, cure diseases.

And there is a man-versus-man story: fight, steal, cheat, subvert.

Intelligence is multi-purpose. Does high IQ get you Switzerland or Lebanon? There is an extra quality, of being pro-social and cooperative. Call it team spirit. Whether increasing IQ makes a society better or worse depends on the level of team spirit. With little team spirit, high IQ leads to more devious betrayal, and more accurately timed back stabbing. With high levels of team spirit, high IQ boosts cooperation because people see better how to do it, and counters the problems of too much team spirit (group think, purity spirals, doing it our way rather than a good way)