With bitcoin, we are our own bank. So the safety and security of our funds lies within us, our capability to keep and store our bitcoin privately and securely, which we cannot expect from banks to do it with fiat.
Furthermore, bitcoin is decentralized, so it has nothing to do with big names and companies that could back-up bitcoin but the control is given to us solely. This is the best chance for us to accumulate maximum amount without the interruption of other group or entity, unlike fiat that is monitored by the government and banks.
That "we are our own bank" became obsolete when people started to put billions of dollars worth of bitcoin into exchanges. Today, if you check the cold wallets of biggest exchanges, you will realize that 10+ billion dollars or more are already in cold wallets alone. Meaning, we are not really our own bank, "some" are, they keep their money with their own wallets and that is great, but in real life you could have jus cash and not use banks too, very rarely done, and very rarely people do the same with bitcoin.
Most of us are using exchanges like banks in the crypto world. "Not your seed/keys, not your coins" was a big warning in the crypto world back in the day when too many exchanges exit scammed, but people didn't learn and they kept doing it.