1) There is too much of information overload. But people want in simple terms.
Let me try to explain in a non-military and non-diplomatic terminology so that you can undestand why China and Pakistan are playing the game they are playing in India's northernmost tip.
So China wants to make it very difficult for India to reach DBO & keep it. With DBO, India has height advantage, as well as distance advantage to attack China (Chinese border is just 8 km)
And for CPEC billions invested from Khunjerab Pass till Abottabad.
And for Tibetan Chicken necks.
So they are trying to push India away from Shyok in north east & Pangong Tso in south East of Ladakh with current aggression.