You were right that paper money has a value, and it can be stored, we cannot argue with that, but the question is, does that amount you put in the bank still the same as the time comes? Let's put it simply this way, $1,000 is already enough in our family to survive whole month or even more, but do you think that figure will be enough in the future? Considering the constant rise of the prices in all the basic needs everyday do you think in the next 5-10 years that amount is significant? I don't think it is. That is the same situation even if you put that amount inside the bank, and guess what? for sure you'll earn percentage depends on how much you deposit by what method? Banks are going to play your money by example lending other people and giving them interest rates as their profit, and the duration? In my country it has minimum of 3 months, so let's just say they can lend it 4 times a year with 2% interest per loan, they have 8% APY just using your money and you get the 2% because that's what the bank promised when you put your money for time deposit. In short, they have 6% profit without lifting a finger and only using words and papers.

That's just a basic breakdown for an individual putting money inside a bank, so how much money does the bank have if all of you guys put your money at the same time? 100% profit isn't impossible to make if we're talking about banks, but that's just them not the individual whose blood and sweat being poured just to make "savings" for their future plans.