you don't necessarily need to store them in your bank account, you can leave them in your house in a safe box underground, well hided, the same thing you will do with a paper wallet...
the problem with fiat is that you can't save them for long time without losing value, because of the fact that bank keeps printing those like mad childrens, you are obbligated to invest in something
bitcoin instead is already an investment, because it has a store of value property
the older generation like to store their money cash in their home, but the younger generation is all for the digital aspect of storing money. beside that, storing $1,000,000 cash money is completely different than storing a paper wallet with $1,000,000 worth of coins. it's much safer as you can hide a small piece of paper everywhere in your house where literally no one other than you can find it. a safe box is easy to spot. even if you hide it well enough. experienced criminals know exactly where to look.