The purchasing power of those 80 people isn't going to start looking insignificant if you change the basis for comparison to net wealth plus imputed future income streams.

Also, global poverty is not the fault of Western riches. It's not something we (Westerners) can do anything about either, except engage in mutually beneficial trade. Most of the world is being held back by bad governance, dictatorships and democracies alike. The West has the only economies of significant size that still have the broad outlines of a true free market system.

However, no human life is average in that respect. Everyone occasionally wants to fix the car, bail mother out of jail, keep the new restaurant open for another month, hire another cook, quit the job, drive to California, or whatever. Some of those variable circumstances can be addressed through insurance, but many cannot. Many of them are more along the lines of "it is my will to do this thing I had not planned on doing, right now."

That stuff, that human stuff? That requires wealth. We can paper that over with "easy" credit, but that's a leaky abstraction, and it really only helps one make the choices that consumers are allowed to make. Just ask a 90yo (hint: probably remembers a particular period of history): wealth is strictly better than credit. That's without even considering transaction costs.

ps. try getting a reverse mortgage without first owning a house...