Actually if you look at Ibbotson data from 1926 the risk free rate (T bills) is usually small and positive in real terms. Albeit smaller than bonds and smaller still than stocks.
Today it is negative.
But I also agree that naive investors look only at nominal rates and aren't sophisticated enough to think in terms of real rates.
The other day we had a poster hoping for more inflation so that nominal rates on I bonds would go up.
In any case, today we have very low rates in nominal terms and negative in real terms.
So both naive and sophisticated investors are not happy with their fixed investments.
I think you suck it up and remember that the primary purpose of fixed income is not earning the coupon.
It is keeping a part of the portfolio safe and reducing overall portfolio volatility to an acceptable level.