As for me, fiat isn't losing its value despite the increase of people who are using digital currency. Cryptocurrency still has to go through before it surpasses fiat. In our country, people who are using our local wallet still convert their crypto into fiat to spend it with their necessities so I guess we're still far from replacing fiat. Both bitcoin and gold still rely on fiat at some point.
Fiat is losing its purchase value,the things we bought with one dollar few years back need 5 dollars for the same things but its unlike in cryptos the value just keep increasing and the gold is just maintaining its value for very long time.