I think there is a difference between buying into a 3% front loaded mutual fund and investing in a restaurant in downtown Miami. The first is suboptimal and almost certainly won't beat the market, the other is likely to lose 100% of principal invested within a few years. I guess the equivalent for a non-wealthy person would be to invest all their money into lottery tickets.
With Vanguard/Fidelity/Schuab you can make only 45k/yr over your whole career, put the $5500 into an IRA in VFIAX/VOO starting at age 22, and have an retirement income of $58k/yr (not including social security) when you retire. This approximately 1.1-1.5 million in retirement is enough savings IMO, and allows you to pursue whatever career you want, e.g. nonprofit/teaching/part-time with much less anxiety than a traditional pension or more active investment like a restaurant.
Maxing out an IRA is only a 12.2% pre-tax savings rate for someone with a $45k/yr income. This is not difficult at all, however it is important that it starts in the early 20s.
