The problem with those studies is that they’re based on cashflow. Yes more cashflow doesn’t increase experiential happiness after a point.

But it turns you into a wage slave. Turn off the cashflow and everything collapses.

Wealth gives you happy levels of cashflow regardless of working for it right now. Hence it creates freedom.

You won’t be more happy by having wealth, you’ll be more reliably/resiliently happy.

You're right that they focused on income (not quite the same as cashflow but it's a good point).

What was interesting is that above a certain income, life satisfaction actually began to decrease. I wonder if there is a similar corollary to wealth.