Investing in Bitcoin and also saving money in our banks are two important things, you can't invest in Bitcoin and don't still have some save in your bank that's very wrong, remember you are investing with your leftover fund in bitcoin which is your discretionary income money you won't be needing for a very long time while the one in your bank account is the one you will needing anytime to sort out your personal needs by getting it back either going to bank or by going any point of sales POS joint to withdraw your money while you still accumulate Bitcoin and hodl so it is much important to invest into Bitcoin and also have some huge saves in your bank very very necessary.
I understand your point here but I don't think the Op was referring investing or saving the money that you'll want to satisfy your daily needs rather, the money that's set out to be saved or invested for future use. Just like investing in crypto with the hope of making profit at the end, some investors also make profits by saving their money in the commercial banks using fixed deposits which also generate a certain percentage as profit at the end of the fixed duration. So the OP is asking which is better between saving in banks or investing in Bitcoin.
That said, I personally believe that investing my money in Bitcoin is the safest means of investment and considering the fact that Bitcoin have very little risk management, I'll always prefer it to saving in banks