People need to learn basic skills such as reading, writing and simple arithmetic to perform even the most basic of jobs. Also, a general understanding of how the government in the country works is necessary for being able to survive independently. Managing finances, balancing a bank account and even paying for items at a grocery store are dependent on skills learned in school.
The more education a person has, the more career opportunities open up to them. Going to school and learning skills above and beyond just a basic skill level is important for a person to not only get hired for a job, but for getting a career level job with a good rate of pay. This is also important in career fields that offer a large amount of opportunities for long-term career advancement and security. For example, in the 21st century, it has become extremely common in many career fields to require strong computer skills. Without computer classes that are offered in many schools today, the chances of landing a decent job are greatly diminished.
Parents can teach children to behave appropriately, however this only goes so far. To put these parent taught social skills into practice, it is important to attend school. Learning by the experience of being with peer groups is an enormous benefit in learning how to fit in well with society. There are many different types of people in the world, including difficult to get along with people. Bullies are common in school, and it is important to learn by actual experience how to deal with people like this. School is a microcosm of life, and so if a person learns to get along well with different social groups in school then the chances of having successful relationships once they graduate are enhanced. The interaction with a variety of people and personality types is a learning experience in itself that is beyond book education.
School is generally organized in a very structured way. Structure tends to keep kids on task and engaged in the activities that they are engaging in, while at the same time offering a safe environment. Learning in a structured environment also helps kids to feel that they have successfully accomplished a task at hand. It also teaches organizational skills, which is important for career opportunities in the future.