I'm not sure that's true? The stock market is up quite a bit if you look back a few years. Your average boglehead-style buy-and-hold investor has probably done very well.
EDIT TO ADD: Sincerely, thank you for your comment (and the replies providing additional context). It's given me some much needed information to go research (ala Boglehead investing).
What does this mean?
Basically: buy a few index funds, don’t sweat trying to beat the market, you’ll come out alright.