ATMs and credit cards both have fees (I believe you are joking). It may have zero confirmation time but It's possible to chargeback and get scammed. Lightning Network should give us the ability to make micro-payments and without waiting for confirmations too. Banks control your money, you don't. I see no reason on why fiat is better than bitcoin.
One reason why Fiat currency is better than BTC - it is accepted everywhere! Bitcoin will never get that mainstream, at least not anytime soon. In the future tho it might get a bit more popular but no country would switch Fiat currency for Crypto.
I agree that cash is better than bitcoin because cash is accepted all over the world without any controversy and doubt.It is under the control of a central bank so cases of fraud are less.Even a common man uses cash as he may not have any internet accessibility and knowledge about the cryptocurrencies or bitcoin.Not everyone knows how to operate bitcoin.Every transaction is done through cash and is recorded.But if transaction is through bitcoin,we cannot track the money.Traditional money has established itself from a long period of time.