It assumes nothing of the sort.

Even if your retirement budget (or at least your budget in your old age) is $30,000 and you have $164k invested (the median according to https://www.synchronybank.com/blog/median-retirement-savings-by-age/, this can help you optimize what you can draw from your savings to add on to your Social Security benefits.

So, it’s useful for more than half of Americans. If it’s not helpful to you, I hope there’s something else out there that is.