many people don't know the reason why they are saying that there's no money in the bank it is because in the bank bankers use our money to trade and also borrow some people secondly the Central Bank of that particular nation maybe they are lacking printing of a new currency or the money is being hold my politicians for their own selfish interest this is one of the things that scarcity of money in a country so you cannot blame bankers that much because maybe they probably might come from the government not to them but sometimes bankers use our money for trading exchange mostly
Each bank is guaranteed to be connected to the central bank, where they also control the movement of both incoming and outgoing money and help if there are difficulties at the bank by providing assistance.So as you said, if the bank has no money, it is certain that all of it is usually used to be turned over and lent to customers to be able to profit from the interest generated.So it could be that money actually no longer exists, and the central bank should have to intervene so that there is no money vacuum in the bank if the mechanism is running properly.
Indeed, it often happens that many politicians play and manoeuvre banks for their own interests and their scope. It is difficult to monitor this because, once again, the power cannot and is not empowered by politicians, some of whom are also playing; this usually happens in developing countries.So the scarcity of money in banks always involves many sectors and is sometimes difficult to control if there is no good mechanism from the central bank.