Here's my complaint about fiat money.
Let's pretend there's no money, we are neighbors who barter with each other. One weekend, we agree to a deal whereby I paint your shed in exchange for 2 chickens. We both have come to the agreement that my labor and time is worth 2 of the many chickens you raise in your yard.
So I perform the job to your satisfaction. But I don't want the birds right now, maybe my freezer is too full, or maybe you don't have enough to spare at the moment. So you write an IOU telling me to come back in a few months where we can settle.
Problem is, when I come to collect - you now declare the note is worth only ONE chicken. What happened to the buying power of my labor, between service and payment? This is a scam, and if you don't honor our agreement I won't do business with you anymore, and your reputation on the street is suspect.
This is analogous to fiat dollars. The instability is problamatic.
I take issue with your statement that all money is fiat. There's a world of difference between creating numbers in a database and actually twisting gold (or other metal) out of the ground.
Empires have come and gone, and so have their fiat currencies. Every fiat currency ever invented has failed after being inflated into oblivion. Hard money cannot be created so easily, and is therefore something of a protection, I think.