What exactly are they keeping their assets in? A house that they can't sell and make that worth liquid? A retirement account they cannot withdraw without huge costs and compromising old age? Where else?
The fact is that it has never been easier or cheaper for individuals to invest in a reasonably diverse portfolio and grow their wealth. The problem is that the average American has no wealth to grow:
https://www.cnbc.com/2017/08/24/most-americans-live-paycheck...
I am fairly convinced, based on the spending attitudes of many people I know, that even if they had extra money, they still would not invest. They would just spend it on a new 4K TV, new car, or a bigger house that they don't need. Most people seek immediate gratification.
2) Home equity line
3) Retirement account
It's not painless. Losing money never is. But you said "wipe out" not "will pay fees and lose 10% of net worth."