Target Date Funds simplify the investment process for investors, as such funds oversee changing asset allocations through time. A secondary benefit is that with these "set it and forget it" funds, investors are less likely to try to time the market. This is good since such activity generally hurts (rather than helps) most investors. In fact, staying the course allows investors to benefit from downside market volatility, as continued investment enables investors to buy more shares at lower prices, so-called dollar cost averaging. See article here, WSJ.
Dolvin, Steven D., "Target Date Funds and Dollar Cost Averaging" (2016). All Chapters. 156.