Why is independence important for a country?

Essentially, it is the very reason of existence for a country.

Explanation:

Independence is important for a country because it’s the very reason of the country’s existence. A country or a nation wouldn’t exist or have a distinct identity if it weren’t independent at the first place. The idea of independence become prevalent in the mindset of a distinct group of people when the belief of transcendence as an individual nation becomes prominent whether it is due to indignation or necessity of self-identity or any other cause for that matter.

This phenomenon can be seen in the Kashmiris of India or the Baloch of Pakistan or the Catalans of Spain. Most of the countries we see today got independence from an imperial force. One may ask why some ethnic groups, fundamentally disparate from the countries they are part of, are content with their circumstances despite having no independent country of their own such as the Bengalis or Tamils of India. Well, these groups are intimately assimilated to the countries they are part of, their interests are coherent with their national interests or they will be more benefited if they stay with the nation rather than having an independent country of their own. The Bengalis of India are Indians as much as they are Bengalis.

i think its the outcome of people's preferences.

then its a law the end