I have always hated this saying because it's worthless without the context of who is getting the money.
I grew up poor - money definitely made us happy because we could afford to move out of my aunt or my grandmother's house.
Everyone loves to cite the study that "above $75,000/year money doesn't make you happier" - without realizing that it's simply saying that there are diminishing returns above that point (standard economic marginal utility concept), not that overall happiness goes down.
The reality is that more money gives you different problems, not more problems and in fact opens up a world of opportunities that can keep generations beyond you above that $75,000/year mark.
Money is about what it enables and that is where happiness comes from. As a wise man once said:
"Money can't buy happiness [but it can buy] a WaveRunner. Have you ever seen a sad person on a WaveRunner?"