Firstly, people need capital for their economic development, or need urgent cash aid on some trouble when they're hopeless to obtain interest-free loan.
Secondly, bank loan offers low-interest loan to those people in need. If people turn to private loan, they will be impacted with high interest.
There are 3 main reasons for bank offer loan service to those people in need.
Firstly, bank is traditionally generated for credit and debit. And bank has responsibility to offer loan service to those people in need.
Secondly, most income of a bank is happened from the interest of loan service.
Thirdly, for the stability of the society, to help those people in need, and to strike those illegal loan service all over the society, official banks tend to offer low-interest loan service. To survive themselves and compete with official banks, those nongovernmental banks also need to provide loan service.
Therefore, bank loan service is always necessary to both banks and borrowers.