I think there's a threshold in estate size when it makes sense, but for example, my husband and I have a car (on which we still owe thousands), a small house (which we own about 20% of), and about $3000 in savings. Oh, and my TIAA-CREF account and his 401K, neither of which are particularly robust because we've never made all that much money (and, as we're both 50, those aren't going to get much bigger).

Our levels of life insurance don't actually change that situation much. I'm kind of uninsurable due to having had cancer, and I can't convince my husband that life insurance beyond $100000 might be necessary given that my disability income is about half as much as he makes in a year.

I'm not convinced that a financial guardian would make sense under those circumstances, especially since such a person would almost certainly have to be paid.