The index strategy has never been *optimal*. It's just superior to the vast majority of real-world, professional investors' returns.
Yes, there are some exceptions like Warren Buffett, which has fantastic returns in his past (and present). But if you were an investor when he opened his first private fund, you could not have differentiated him from any average manager.
Anyway, to create an optimal strategy, you would have to get some advance knowledge of future events, by crook or by cunning modelling. All financial models have broken down in time, some catastrophically. Market-timing works well, except when your timing is off. Hedging works well, if your hedge really counter-balances the rest of the portfolio at all times. You can't count on that. Even "strategic" allocation (meaning timing the market with portfolio composition changes) mostly relies on soothsaying.
IF you have the chops to jump in and do the financial equivalent of getting an olympic gold medal, go for it; I do not have the drive, talent or deep pockets needed so buying the market and getting "average" returns is perfect for me.