tl;dr summary: If India doesn't formalize Quad, a 1962-scale defeat is very likely. Moscow is dissuading Delhi from entering the Quad. Moscow must be having something on Modi (carrots such as Afghanistan mining access or sticks such as killswitching Russian hardware), to dissuade him from joining Quad. The Chinese calculation is Modi will be fed enough NAMardgi coolaid that he'll try to fight China alone. And Beijing is counting on it.
Beijing has been cucked in the South China Sea by America's 100,000-ton BBCs, and is desperately looking for a military victory against a formidable (read: nuclear armed) opponent, before 2021 (CCP centenary year), so Xi's pee stain on the Great Hall of the People is indelible. Xi would have had his glory in 2021 if Jiang Zemin didn't spoil his plans with COVID-19 (while killing 1 million people around the world and wiping $10 trillion in global wealth). An Indian capitulation against the PLA now, will make China the undisputed leader of the Himalayan region.
Quad is the key. Quad is how India ensures 2021 ends in a disaster for Xi, the CCP corrects itself through its usual blood sweat and tears; and the rest of the world stops taking collateral damage for Beijing's internal politics.
Now you know why the west is increasingly hostile toward the CCP. It's the world's largest single political party, in which internal disputes play out on a global scale. And with China's growing economic clout, rival factions within the CCP will start waging proxy-wars involving other nations. In a democratic system, local elections contain much of these disputes. It will be a shit show.
India must win or the world is fucked.