DJIA from about 2007 to present. The low point is where he was 50% off. The current high point is only about 50% higher than 2007, so he wouldn’t have theoretically doubled his money (assuming a very average marketbasket of stocks), but would have had a 50% return over 10 years, which is not great, but not bad, either, given volatility in that period.
More generally, people who stayed in the market or bought in did very well. Most Americans can’t participate materially in the market or, if they suffer losses that big, have the stomach (or can afford to) stay in. So I wager a lot of people who lost a lot didn’t regain it even as the market soared in following years.