I guess it depends on how actively you manage your portfolio. Buying stocks that are trending, cutting losses quickly and leting winners run has worked exceptionally well for me in the past 20 years.Mild, not incredible.
Understanding Momentum Investing - (alphaarchitect.com)
It all depends on the market cycle, which you can't predict. Sometimes stocks mean revert. Then it's costly to get rid of "dogs" about to recover and replace them with "strong stocks" that are about to underperform. It is good to get rid of stocks that continually drop and may eventually go bankrupt. But that's a quite small part of the index.