Going back to the S&P 500 and why its a false argument against any financial manager.
The S&P 500 constantly changes, based on past performance, not future ones. Companies that don't perform gets kicked out. New companies that performed, gets listed in. The list constantly changes. S&P 500 in the year 2000 is not the same list as the S&P 500 in the year 2020. If you have invested in companies in S&P 500 listed in the year 2000 you would have lost severely---only six to seven companies from the list in 2000 is still with us today in 2020. It therefore is not a good predictor of future performance, the companies you invested in 2021 may not be in the S&P 500 list in 2031.