Actually we were able to, and are.
Uyghurs and Tibetans combined are only 1% of China's population, even in their own native provinces they have Han majorities.
India on the other land has to fight and lose wars over lines drawn by white British men like "Sir Henry McMahon".
But don't worry, Partition 2.0 will save you. And you know it's inevitable, just like Indians themselves know that India was created by the British, but will only admit it to each other. And India has the 2nd largest Muslim population in the world, which is growing at an exponential rate.