I was one of those who lost most of what I had during the GFC, but it was because I had followed the advice of a portfolio manager who recommended that I leverage my stock to buy more shares. When the value dropped, I was forced to sell what I had at below value to pay the leveredging debt.
Fortunately, I owned my land, car and had no other debts, so I didn't become homeless as many did. I was 55 at the time and had been living on the income - so the loss of capital meant nothing to live on. I retrained in aged care, and worked as a carer in residential hospices and the community.
Eventually, when my mother died, I invested what she left me in superannuation with green ethics. I survive on that now. It's no more than a public pension, but if I'm careful how I spend on the basics, it's adequate.
Investing in shares is not necessarily a bad thing.
One key is never to get in debt. Then the rises and falls on the market are "paper" value only. They have no effect until the moment the stock is sold, and then the value is how much it rose since the stock was bought.
Another key is not to be greedy. Anything chasing big profits comes with high risks - without exception. Choose stable stocks with reasonable dividends in companies that have reliable management. Experts research that full time, so if one chooses a stock broker who works for a firm which a large research department, one has a good chance of faring well.