Well, it's true that India is obviously nowhere close to China's development stage and industrialisation level. However India is China's largest neighbour and the only country on earth to be close to China in size population wise, as such they also have alot of potential going forward due to their sheer size alone. They are expected to overtake China in population a few years from now (some say only 3 years from now) . So it will be bad for China to go to war with such a neighbour and sow the seed for a permanent hostile neighbour which they have to be guarded over 24hrs/7.
China has far more formidable and Powerful enemies on its shores in the Pacific, i.e Japan and the US. China will need several decades of rapid growth to even come close to matching these two powers and standing a chance in any confrontation against these two powerful countries, so adding India as another enemy they need to be more wary of will be another added headache which they shouldn't wish if they think things through.
In fact China is the only major power in the world that is still divided and not unified to this day, since they still haven't resolved the Taiwan issue to this day, which in itself is an embrassement to be honest and a strategic mistake. So the last thing they want is a useless war with India that won't achieve anything significant for them. There is so much they are/will be facing in the Pacific which is and should be their main focus and priority, not some Himalayan rocks which can be solved with some calm heads on both sides. In fact if I was a policy maker in Beijing I will focus on mending ties with India and using my leverage and power over both to act as a mediator in solving the border issues with both India and Pakistan and China itself. This will lead to an ushering of a new age for the region and unlock the untapped potential of this region and gain the country goodwill and another added card to be used against the US.
I think China is actually the country that can help solve the current issue between India and Pakistan . However, they will need to be compromises to be made on each sides, something I'm not sure these countries are at the stage of accepting for now. Probably need alot of time to get to that level though.
