I just found a fascinating website which shows how the S&P 500 performed from year X to year Y with dividends reinvested, not adjusted for taxes, but factoring in inflation.
S&P 500 Returns since 2008
How have anyone's results compared?
"If you invested $100 in the S&P 500 at the beginning of 2008, you would have about $366.22 at the end of 2022, assuming you reinvested all dividends. This is a return on investment of 266.22%, or 9.15% per year.
This lump-sum investment beats inflation during this period for an inflation-adjusted return of about 164.85% cumulatively, or 6.79% per year."
Also, Charles D. Ellis on index funds vs. actively managed funds:
https://www.youtube.com/watch?v=YYjvA7U__mk