[codingslave]

Index funds work because weve been in a 20 year long bull market. If the market goes sideways for a decade, or down for a decade then active investing is alot more profitable.

[roadnottaken]

It's been a ~10 year bull market. 1999-2009 was basically flat.

[groundlogic]

That has never happened (as far as I know, in modern history). Of course that's not a reason it can't happen, but I feel like you owe us at least a plausible decade downturn scenario.

[nostromo]

It has happened for specific stretches of time.

For example, if you bought near the top in 2000, you were still underwater a decade later.