1. Ignores income streams from things like social security, reverse mortgages, held away assets
2. Ignorant to future medical advances that could change life expectancy
3. Built on past assumptions of bond yields and interest rate levels
4. higher fees than an equity ETF
5. large discrepancies between each one
6. Bonds are not necessarily less risky than stocks. As yields drop, bond convexity is high, meaning the bond price will be very sensitive to interest rate changes
I have many family members who still have big company pensions from back in the day and also own target date funds in their 401ks so combined with social security income they end up being massively over-allocated to bonds (a pension & SS can be treated as bonds).
[1] https://investor.vanguard.com/mutual-funds/profile/VTIVX (example fund, Vanguard Target Date 2045 fund, 0.15% expense ratio)
According to John Bogle, this has been true for over 100 years. His analysis goes back to 1900.
I personally tell people to invest in index funds if they don't understand investing, but it doesn't mean it will do better than other options. Index funds are only a recent phenomenon.
The biggest issue with index funds at the moment is "group-think". If everyone in America is investing via index funds then when people need money, those same index funds will fall sharply. There is a valid line of thinking where one should avoid stocks with heavy exposure to index funds because those stocks will have the best returns during an equities downturn.
http://theirrelevantinvestor.com/2017/08/31/today-in-market-...
Also, please tell me 1 of those better options?
The link you posted seems to take the opposite view from what you expressed. Batnick is very pro index funds.
The question is if you dont follow the passive ETF/index strategy what do you do? In that regard i suppose its better than doing nothing.