Excess money may not buy happiness, but lack of money causes a lot of unhappiness.

The study you’re referring to was basically that. There has been some follow-up, including www.pnas.org/doi/10.1073/pnas.2016976118 that suggests any plateau, if one exists, is more like $400-500k. The latter study used continuous sampling via go.trackyourhappiness.org, where the former did retrospective, daily, binary sampling, so they’re not exactly comparable. i.e.: if you ask someone 6 times a day to rate their happiness 1-10 right then, you’re going to get different results than if you ask them whether yesterday was a good day.

There’s a whole weird thing people do where they can be quite satisfied with their life at any particular moment, but dissatisfied when asked about their life overall. I suspect that the $75k plateau is more of the latter, where the lack of plateau is more of the former.