We can't realy deny that people still prefer to stored their money or fiat currency in the bank because of security and assurance. But on the other hand, if we talk about investment, people who are engage in crypto world prefer to use bitcoin for their investment because we all know that bitcoin could give you huge amount of profit in just a short time.
First and foremost, this is a very new space and the possibilities of still trying to minimize risks rather than going all in is still there even though you want to believe in the long term potential of the market. This is one thing that would still keep helping to make fiat relevant and then banks to still be in action, asides from the fact that not everyone anyway will end up being a part of the space due to some limitations or the other.
For those who believe in the future of savings and spending with freedom, they will always choose bitcoin anytime any day and it will even get better when we start seeing real life usage. I guess the main issue here is just enlightenment as people need to understand how things should naturally be, but you cannot simply force everyone and we all know knowledge is profitable.