Richer people don't have access to higher EV else their kids wouldn't have very similar relative mobility, they should be richer than their parents. And it seems that the risk of becoming downwardly mobile (absolute and relative) increases along with income. Which makes sense as some sort of mean reversion. Along with the bottom quintile having higher positive mobility than richer quintiles, EV increasing with income doesn't make sense to me.

The family with $500 should keep it as liquid as possible unless they have enough credit to cover drawdowns in income. Other than that - they get the same EV as everyone else. $500/yr at 7% over 40 years will get you $100k. How many people with $500 actually invest it? Historical lookback on 40 years of the S&P 500 gets you real return of 8.77%.