My point is that wealth is not a useful metric. To your point, having surplus wealth on the day of your death is not very useful, especially if your kids don't need it. That's why some people get reverse mortgages, to turn the value of their homes into spending cash during retirement.
On average, no one needs wealth. After all, one can simply work for a wage completely spoken-for, hand-to-mouth, letting the automatic deposits feed the automatic withdrawals, a "good" "professional" corporate "citizen", pulling the traces until the heart stops and the teamster cuts loose the carcass to hitch up the next mule.
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...
