I will suggest that dont put all your money to bitcoin and some of your money must be secured in your bank account for emergency purposes. Any Bank will always give a guarantee their customer that they will secure their money no matter what happened.
In term of solely for security , BTC is indeed a better option ( Im a fan of securing my own belongings ) if you know how to do it properly but in term of solely investment , I would say that BTC is a good but as I said dont put all your money in ine basket only, put some of your money in safe deposits as an investment
Well if by keeping the money in bank, you mean the basic necessary amount needed to live, then okay, but I don't want to sound like some conspiracy theorist, but banks in fact aren't that secure and at least in my country, they have a legal power not to give you your money back. In case they make some bad financial decisions they have a legal need to give you back let's say $10k while the rest they can officialy keep. Also money laying in bank is losing it's value, so it's better to use your funds and invest it smartly.