Sure, you can get lower returns as well by cherry-picking the start and stop dates, especially for shorter intervals.

When economists say things like, "the market returns X on average," they always mean over much longer periods of time than your example.

The figure till 2013 was just food for thought. Inflation adjusted returns for the S&P 500 for the last 50 years are around 7-8%. I'm certainly not suggesting anyone stay out of a S&P 500 index fund, as I wouldn't take that advice myself. However, the return from 2000 to 2024 is not a cherry pick for anyone old enough to have had their money invested back in 2000, as it shows that there has only been a 4.5% real return on the money then invested since the 2000 peak.