That is so true, and in fact the level of income is less closely tied to experiences of financial hardship than you would imagine. I remember reading something a few months ago where they excluded the lowest income earners because it would skew the results. Either because some of those very low income earners don't need an "income" because they are living on accumulated wealth (eg self-funded retiree with lots of assets) and other low income earners have very low expenses (because they have good access to very cheap housing, medical, or they have access to very good support from family members etc). By the same token, people in higher income brackets also experience financial hardship (although usually for shorter periods and to a smaller proportion). It just goes to show you can't judge from the outside.
I agree with you, but sometimes living ok on a really low income just comes down to good budgeting and being very frugal