I don't think traditional currency will be replaced. Bitcoin and other cryptocurrency will be an option. Many of us see the future of bitcoin while other people do not even have the idea of what is crypto. It is not really safe so we have to be careful and learn first the security of accounts when using bitcoin.
I thought the safety that you are describing is the volatility of bitcoin and other cryptocurrencies. And about your concern for the security of accounts, it's about the security of every holder that has to keep their wallets safe through keeping private keys and avoiding storing it on exchanges that don't give them to their users.
I think as a store of value, but not a currency.
Agree with it, bitcoin has become a store of value and we're all preferring it to be like that. Although no one stops everyone from using it the way it was made just many of us prefer it to be a store of value.