Fig 2 of [1] shows high variance of happiness while income variation has only a small effect. There is roughly a 5 % (percent it is?) happiness delta for an inc

Fig 2 of [1] shows high variance of happiness while income variation has only a small effect. There is roughly a 5 % (percent it is?) happiness delta for an income delta of about $ 500.000. However, the happiness delta between the different happiness levels is about 25 %. Would “Income and emotional well-being: It doesn’t really matter” be a better title for the study? Or do I miss something? [1] https://www.pnas.org/doi/10.1073/pnas.2208661120#fig02 https://www.pnas.org/doi/10.1073/pnas.2208661120#fig02