developmental terms

No, I am not at all calling China's capabilities low in terms of creating a war machine.

I am talking in terms of how quality of life has been affected by either of them in places which both countries are calling as their own (see my points in the above comment). While China tries to call Arunachal Pradesh and parts of J&K and its people as under itself, India is what sends the disaster relief resources, whereas China considers blocking natural resources to try and increase discontent of the people living in those areas.

China took longer than India to even admit the increasing air-quality problems in high pollution states,^[although for both countries, the actual metrics being used to report them hardly align with actual types of pollutants and the mitigations in response have been "too little too late" for both] which shows me that the govt. doesn't like admitting facts. And personally, I am fine working with people who fail a lot, as long as they are consistent in communication and don't try mixing lies into reports. Because trustability is an important part of any relationship, which also applies to governments.^[The main reasons I give flak to US govt and organisations is due to their lack of consistency, which makes them very less trustworthy.]

And I am not even going to point out the actual quality of buildings that you might have been a part of your metrics, simply because I expect enough people to have pointed those (and other similar conditions out to you).
While Indian buildings aren't particularly great either, I am in a 10+ year old building which was not designed for earthquakes and has still not cracked (much less collapsed into a death trap) despite multiple of those.

Then comes the destruction of values over the years. China has had a rich culture of thousands of years and any such civilisation develops values and traditions that are conductive to longevity.
But the recent values shown by adults (not even children) from China has indicated an erosion of older values that were developed over the centuries in China. This is not something that happens easily without intervention from higher powers (and I am inclined to think it was the govt, unless you know of any other power that might have to gain from activities that cause this side-effect).
While there has been quite a lot of food adulteration problems in India, there are some lines that people would not cross. Specially the working class (who actually care about values unlike the business class) would never. But the normal people that seem to come out of China to set examples, don't seem to be doing any good for its reputation.

a few hundred acres

It started with a few metres in some cases and has been going on at multiple fronts.
Perhaps PRC needs to stop expecting people to forget the past and start noticing how they contradict their own self.
The tensions have been created by PRC's "an inch a day" tactics, which I honestly see as nothing more than petty (and I am saying this, knowing full well than PRC would want to call India "petty", to help them get more fake points).

For Nepal

And if it really was just about a "few hundred acres" and PRC really worked with a Socialist philosophy, then they would:
a) Not really need to worry about Nepal (a pretty small country with hardly any military power) being any sort of a threat that would require putting effort to take a small amount of land. b) Consider how the small amount of land would hardly make a difference to the people of China, while it would make a big difference to a country with was lesser land than China.

And that is where the inconsistency I talk about, comes in place.

Nepal is an otherwise docile country and I am pretty confident they would have been happy to have partial open borders with some kind of trade treaties in that area.

As such, while you try to play it down by calling it "contentious", Nepal was trying to hide any such transfer or annexation, fearing what exactly? If it were really fairly claimed, there wouldn't be a real reason for that, no?

Hi, I added to my comment. Please check