Answer
The reason for researching the company’s mission and goals is so that You can use this information to show how you will be an asset to the company.
Explanation
Mission of a company the clarity of what your company can do do to its clients and what services can be offered that is with the aim of gaining more clients in order to increase the company's profit and make its profile more appealing. It also describes who the company is and why you as the client you should be part of it.
Company goals are the things which are set by a certain company with the aim of helping the company grow and achieve its objectives.
so when you research the company mission and goals this means you are helping it to achieve its objectives and You can use this information to show how you will be an asset to the company.