This kind of metric is always used to shock and awe in pop media when talking about the GFC, but it's not how actual investment works. In practice most investments are DCAed.

No person puts all of their retirement savings into QQQ or SPY at the peak and sell it off at the trough. Instead folks drip their savings into their weighted portfolio and withdraw money from their weighted portfolio as expenses accrue. Now obviously the GFC was a huge deal, but this sort of facile understanding of stock markets always leads to big misunderstandings. There's a reason Monte Carlo analyses of these events are used to model these scenarios.

(Though I imagine there were many people who tried to re-balance their portfolio into a less equity-heavy model abruptly during the GFC and based on equities performance at the time, it was probably the right move as long as taxes were taken into account.)