I lost quite a bit of my 401 k in 2008. In 2016 I put all my eggs into a Stable Value Fund, since retirement was just around the corner and i was not willing to lose anything. It does not give you the big gains one could get with being heavily invested in stocks. But, I did not loose anything over the last few years.
Money loses buying power over time. Inflation in normal years is maybe around 4 percent. The rate of return on say Vanguard's Stable Value Fund is around 2 percent just to make the math easy. Represents a 2% loss in buying power each year. Adds up over 10 - 30 years.
Not disagreeing with your choice. Everyone has different risk tolerance. Important to understand the full implications of low risk low return investments.
The numbers are not exact but representative.