That would be a bad idea when the issue right now is the race for tech. A conflict would cost lives and resources. Even if successful in taking those places, they would become a big ball and chain in such a hypothetical scenario due to insurgency, and the fact they are less developed, meaning they will be an economic drag on the economy (unless you ignore them and leave them less developed but that could breed more resentment and fuel insurgency). Time and resources would need to be spent on developing them, which is time and resources diverted from taking the lead in technology. The incorporation of such areas would also put other neighboring countries even more on their guard and feed the narrative of China being expansionist and bent on world conquest.