I think you'd have to plot a curve based on the potential reward of betrayal... I suspect that many Americans* would have their 5th closest friends committed or worse for low 6 figures. If in ~dire straits, as about half all Americans are, that number could get much lower.

* If my use of the word 'Americans' above is triggering, feel free to substitute it with 'people'.

Yea, this project gives less "my contract partners will benevolently read my diary after I die" than "enabling and incentivizing my closest friends to hold a vote to redistribute all my assets amongst themselves"