Bitcoin provide easy access to ones savings. With self custody all the control are in your hands, no need to follow any rules and regulations or limits. Moreover your savings appreciate in a long term. Banks operates base on the rules and regulations given to them by the governments they collect tax, always give withdrawal limits to their customers.So it is that freedom that people see in Bitcoin is what give them interest to save in it.
That's true if you look at it as savings and control. But in terms of usage, Bitcoin is not yet widely accepted. This also becomes a limitation for people who have both Bitcoin and money in the bank.
I still keep money in the bank, the amount isn't much different from what I have in my Bitcoin wallet. Especially for need-based funds and emergency funds, I will keep them in fiat in the bank.