It also depends on what being in the bottom 50% gives you a claim on. If you have no net wealth, but a Scandinavian-style social safety net (not just retiremen

It also depends on what being in the bottom 50% gives you a claim on. If you have no net wealth, but a Scandinavian-style social safety net (not just retirement income, but healthcare, free access to arts/culture/parks and so on), you can still live a good life. "Does the 80th percentile have an outsize claim on lifelong wellbeing relative to the 20th percentile" is a better metric than just looking at bank balances. Also have to consider age effects, to what extent people move naturally up and down through the centiles through early and late working life and retirement. Looking at net wealth centiles in isolation doesn't tell you very much about how a society works.