Keep in mind that the "140+ is genius" is not completely true, since different tests may have different standard deviations. One of the Mensa tests I took in the 80's had a standard deviation putting genius level at 132.

I agree that high IQ definitely correlates with happiness and/or success, but with one strong caveat: mental illness.

I have two friends with IQs in the 150 range who are also substance abusers. Both of them are self-medicating bipolars, and their happiness and success levels are very low.

In high school, one of the highest IQ people was heavily into weed, and suffered from gender dysphoria. He was obviously the most brilliant person in the room, and maybe his high IQ improved his life over not having a high IQ, but he was in hell.

That being said, these are the minority of high IQ people I'm surrounded with. Of the group, I'm in the top 3 at 160+ (depending on the SD) and I'm likely also the most satisfied with life.

My spouse is comfortably in the top 1%, and though they suffer from some mild mental illness, they are also in much better shape than your average bear.