And you can see it referenced in absolutely every anime that has an excuse to have a giant skeleton. Hell there is a show airing currently that references it in the official promo poster or whatever it’s called. Once you notice it you can never stop seeing it.
They said invested, not ‘put in a checking account and drawn down’. Even 5% returns would be 50k annually, which is already more than the median individual income. Actual return on the S&P 500 for the last 25 years has been around 8%.