Because you don't care about the number in your bank account, you care about what you can buy with that number.

Park your cash in a 5% instrument for a year and you can still afford 3-4% less stuff than you could at the beginning of the year.

That's fine for me with a mortgage, but less retirement headroom for many older people.

Cash was paying out plenty a few years ago.

Because inflation was still anywhere from 6-9% on average, but was higher than that for things like housing, healthcare, education, food, and transportation. Holding cash is not "paying" anything, even though you can't see it happen, the purchase power of that cash has deteriorated massively in the past 3 years.

I personally have a hard time going out to a restaurant and getting a 2 person meal for less than say 30-40$. Car market is absolutely through the roof. Housing market, although cooling slightly, is still through the roof. Our base rent went up 15% last year. Gas is now double in my area.