system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why won't China let Tibet be an independent country?

From everything I've heard, Tibet is dirt poor, ethnically a totally different country with a very separate history, and contributes little to the Chinese economy and society.  Why not just let them go?
gpt
Just *because* they can control it. No country wants to cut away a constituent part of it so long as it can still be managed without negative consequences.

Apart from controlling a ton of people in Tibet and gaining access to what resources it has, it also also allows China to keep an eye on the rest of Central and South Asia.

PS. Don't think that this is because China is authoritarian or anything. Many countries have it in their constitutions to maintain territorial integrity at all costs. Places are only 'let off' when they become too much trouble to be worth it, for eg. India or the US getting independence from the UK.