Anyone who has ever posted a job advertisement knows that the majority of the received applications are not going to fit the role. Some are too junior, some way too senior, some don't mention the basic skills required for the job, and some don't meet any standards of a well-written job application. Also, if you have ever done this, you know how extremely time-consuming it is to screen 200+ applications.
Have you ever interviewed someone who seemed like the perfect fit for the job on paper but during the interview, you just didn't have the "feeling" with them? Maybe the candidate did everything right during the hiring process but your gut was telling you that something was off?
Company culture is the combination of the shared values and behavior of the people working for the company. Cultural fit is a crucial building block in employee happiness and the lack of cultural fit can be harmful to both, the employee and the company.