Well, I think that everybody who is dealing with or in cryptocurrencies has to acknowledge that this stuff has not found it's place in finance in the first world...yet
The fiat system has still advantages and it will take a couple of more years for crypto to settle in. I'm not saying that fiat will be replaced, tho.
The biggest problem of cryptocurrencies is the fact that mistakes are irreversible. So imagine the average ETer using crypto on a frequent basis. Typos, phising, using a wrong adress, sending the private key instead of the public key, poof your money is gone...and you cannot call Mr. Bitcoin to ask nicely if he could undo your whoopsie. This is just not practical for the 1st world population which is used to delegating responsibility.
I bet 90% of crypto critics haven't even read the Satoshi whitepaper, so it's inconceivable that you ask Mom and Pop to get put in a couple of weeks of work to learn a new financial system. If stuff isn't self explanatory, it doesn't work here.
It's just not ready yet.
However, everybody should be aware of the fact that almost 25% of the worlds population does not have access to banking in general, even more suffer from corrupted government, capital controls, hyperinflation. But 6 out of 7 people own a mobile phone which is everything you need for crypto transactions.
In other words, fiat systems depend on the people who govern them...which is fiat moneys biggest issue and on the same hand cryptos biggest strength because it's decentralized.
So at the moment it's not a matter of crypto being better than fiat or not. People have to understand were cryptocurrencies fit in.