To back it up some. This is from 2018:
https://money.cnn.com/2018/01/31/retirement/retirement-savings-stock-market/index.html?iid=EL
I think you're absolutely right to question whether keeping 100% of your retirement stash is the right way to go at your age, or for any age at that matter.
And if history is any guide, its demise will likely come via a major setback, with a near 60% drop in stock prices like the one from late 2007 to early 2009 not outside the realm of possibility.
But even knowing that, I don't think the answer is making a move as radical as shifting your entire nest egg into a safe haven. One reason is that, for all you know, making such a move now could be way premature. Over the past several years, Cassandras have predicted the imminent collapse of this bull market for a variety of reasons -- the downgrading of U.S. Treasury securities in 2011, Brexit in 2016, the election of Donald Trump -- and yet it's still going strong. If you abandon stocks every time you get jittery about the economy or the financial markets, you may lose out on some impressive growth in the value of your savings.
Another reason I'm not a big fan of investors fleeing to "safer investments" is that the investments they chose sometimes aren't as safe as they think they are
Besides, even if you do manage to get the timing right when exiting the market, you've then got to decide when to get back in. That's hard to do in real time as opposed to with the benefit of 20/20 hindsight. Get that decision wrong and you might miss out on the often explosive gains stocks' generate in the early stages of coming of a recovery. For example, stock prices skyrocketed 39% in just the first three months after hitting bottom in the wake of the financial crisis.
So rather than trying to figure out when to get in and out of the market and which investments really offer the safety you seek, I recommend you set an investing strategy you can live with in all sorts of market conditions. And by that I mean creating a mix of stocks, bonds and cash that can generate reasonable returns, given the amount of risk you're willing to take, and how long your money is likely to remain invested.
But what you don't want to do -- and this applies whatever your age -- is to get into that Wall Street "risk on-risk off" mentality of jumping from stocks to bonds or cash based on where the market appears to be headed in the short term. When it comes to investing the money you'll be counting on in retirement, you want to develop a rational, disciplined strategy that balances risk and reward, not engage in a never-ending guessing game you can't consistently win.