A $200k family might pay $37k in taxes for fed and state. If a family is making $50k, the taxes they pay by proportion and rightfully are much less. Taxes is one equalizer. Sometimes the people with the largest income are paying off their houses much fast with their extra income.
No doubt if cars and house are paid off, a small income will suffice.
One big money spender is to fund/put multiple kids through college and let them come out the other side with little or no debt.
So when a family pulling in good bucks reach 55, they may be piling up a lot of extra savings.
200k-37k > 50k-anything. Equalizer?
If a family makes 200k and isn't wealthy then they wouldn't be wealthy no matter what they made.