Disengagement serving both sides is undeniably true because India claiming what China considers part of its territory (as much as I consider India's claims here more justified than China's despite neither side having ever settled there including Tibetans), was simply not going to be allowed unless India offered certain concessions elsewhere. It pays India nothing to continue patrolling up to F8 and associated sections along that particular dispute. It pays China nothing to allow India maintain increasingly hostile attitudes against it by occupying so much of the disputed stretch. If India backs off to F3 then China is happy to oblige with removing PLA from occupying 80% of the disputed land. From China's POV, India backing behind F3 is an improvement to India patrolling up to F8 where both sides intercept one another and confront so frequently since the turn of the century. Also China probably was growing worried with India's build up in Ladakh and understand that the IA can overwhelm that area far quicker with far more troops. Stopping Indian buildup of forces and infrastructure was priority 1, stopping patrols a lower priority. In exchange PLA stopping build up is probably less expensive a cost for China since India can make far better use of military infrastructure in Ladakh. But it remains to be seen how both will keep their promises.
Recent ceasefire with Pakistan was also agreed to by India in the last few weeks. It may be a case of India always hoping for a ceasefire along the LOC but Pakistan agreeing to it should also indicate a new understanding that India is ready to play nice with everyone and NOT a case of Pakistan and China are somehow both afraid of India which seems to be the assumption by some. The opposite is if anything true. Pakistan demonstrated ability to go into conflict with India and hold its own... by itself. China held almost the entire disputed territory for an entire year and while India China side didn't really use any true military capability, India recognised that fighting even the western theatre command PLA was not something it wished to do.
Considering that India military demonstrated an inability to "handle" and defeat either side (in China's case, it wouldn't really even engage) and adding to that India's internal turmoil (for the moment), it makes sense for India to agree to certain terms even if those are not broadcasted to the Jai Hind crowd, as obvious as it is to everyone else. Pakistan ceasefire agreements (mutual!) didn't come out of nowhere and no Pakistan isn't scared of India, if anything Pakistan has never enjoyed such an overall good position as it does/did before ceasefire. Agreeing only indicates India has provided certain promises that Pakistan sees worthwhile. Pakistan has not been afraid to engage India and respond when it was weaker and when India was more focused, stronger, and more stable. That was/is anything but the case even with disengagement along LAC. The disengagement is still a delicate thing at the moment and Gogra, Depsang, and Kailash ranges are still not addressed by India MoD as far as I'm aware so far. They said they would be disucssing the matter with the public within 2 days back around Feb 14th. Do we have updates on those from the Indian government or MoD?
I've already explained that Idnia never patrolled up to finger 8 and showed eveidence to support that, but I guess we will never agree on that.
China has withdrawn from all land it has occupied and agreed to stop patrolling disputed territory, that is as close to staus quo ante as you can get.
In Depsang, China is at the same position it has been since 2013, which is why the Indian government hasn't considered it a part of the recent standoff. And in Gogra, both sides are on opposite ends of the LAC, so it is not as bad as Pangong.
China has not stopped infrastructure construction on the Indian side. In fact, the original Galwan bridges taht triggered confrontation between Indian and PLA troops have been completed. And the DSDBO Road has been secured which was one of India's strategic goals. Despite what some say, Chinese positions in Depsang do not threatan it.
As for the LOC ceasefire, it is clear you do not know much about recent Indo-Pak dynamics. Both armies regularly hold talks on upholding the 2003 ceasefire, but after August of 2019, Pakistan refused to discuss them. The fact that it afgreed to what India has been asking means that something has changed. Perhaps it could e related to the disengagement deal and Chinese retereat, but we can't know for sure.
Just go on PDF and see what members there have to say, most are unhappy with the ceasefire since it benefits India post August 2019.