The “mean” and “median” income tables don’t really prove jack sh!t as to household disposable income or quality of life.

A “retiree” or similarly-situated younger “heir” living in a paid-off house with low taxes can live very well on $40K to $50K, even traveling several times per year. If they are not inclined to travel, they can live quite well on <=$40K per year, even MUCH less. Keep in mind that many of these people pay little (if any) income taxes.