Why do banks do with some of the profits they make by loaning out the money in their customers savings accounts?

Banks use some of the profits from loaning out money from customers' savings accounts to cover operational costs, pay interest on deposits, and invest in their own growth initiatives. They also allocate a portion of these profits to build reserves for potential loan defaults and regulatory requirements. Additionally, profits can be reinvested in technology and services to improve customer experience and expand their offerings. Ultimately, this cycle helps maintain the bank's financial health and stability.