People need government to protect their inalienable rights, and prevent other power structures from taking over. A government is an agreement among the people that forms a higher power structure that protects citizens from tyranny. In the United States, the government protects life, liberty and the pursuit of happiness.
The government is also important economically. The government controls the context of how companies are able to do business. Without the government, currency would be unstable, there would be no legal foundations, such as contracts or patents, capital and labor markets would become volatile and foreign threats could cause problems in the market. The government also regulates companies as needed. For example, the government may put a limit on hunting or fishing.
The government helps to regulate and restructure the marketplace, and make competition prevail. This helps to keep companies progressing and innovating. For example, if a bank becomes too powerful, the government needs to be able to restructure the market. The government also ensures that citizens have sufficient infrastructure, such as paved roads, airports and other essential transportation functions.
There are government businesses that operate efficiently, such as the U.S. Postal Service. Consistent service is expected and demanded by the people, and the government ensures that post offices stay open, and that employees have job stability. Private companies are not able to guarantee the stability needed by citizens and employees in many crucial professions.