This is one of the biggest problems of the crypto market today!
For most people "cash out" still means trading back into fiat money. And this is a big problem because it affects the bitcoin price more than it should be.
If only people would cash out their altcoin revenue by buying bitcoins, the btc price would be way less volatile and bitcoin would be what it is supposed to be: Protection from inflation.
The reason why people do still cash out into fiat money is that they don't know how fractional reserve banking works.
If they finally would learn that inflation is theft and fractional reserve banking is debt slavery, than they would rather cash out into bitcoin and the mechanics that lead to economic inequality would finally be killed of.