Why is there a residency requirement to become President? so no young people will be President to ensure someone is mature enough to prevent non-citizens from being President so a person will be familiar with American issues

Answer can be the last choice, so that a person will be familiar with American issues.

Being a president, he will be the one who has the final decision of mostly all the related issues in the country. If the president has a lot of knowledge in terms of political and economical issues of the country, it means that he will be a good president.