Why is the queue longer in the bank?

Gist: Outside the window of a bank were crowded with the middle-aged men who were carrying the account in their hands and waiting for the one in the front inside the yellow line dealing his business. The queue became longer and longer, and many people began to lose patience. Only when their hair turned white, can they have access to the service.

It seems to have long been the case with waiting in a long queue in the bank. As for some “popular” points, it takes one or two hours to deal with one specific service. Why does the queue become longer and longer with the banks dotted everywhere. According to the information from the internal organization of the bank, “the sharp increase of the agent service” is the main cause for the longer queue. Consumers have become unsatisfied for the long queue in the bank. Since the bank charges this and that, why does it have the customers wait all the time? Why can’t the bank establish more branches?