Final answer:
The major advantage of a federal system of government is that it promotes local autonomy and adaptability, allowing for governance that is responsive to regional diversity and encouraging policy innovation.
Step-by-step explanation:
A major advantage of a federal system of government over a unitary system is that federal systems promote local autonomy and adaptability. Unlike unitary systems where power is centralized, federal systems are designed to allow individual states or regions to have autonomy, which can result in policies that are more closely aligned with local preferences and needs.
This division of power helps to accommodate diverse viewpoints and encourages innovation, as states can experiment with different approaches to problems. Furthermore, by allowing local decision-making, federal systems can be more responsive to the unique cultural, social, and economic circumstances within different areas of a country.