George Curzon, the former Viceroy of India in the early 1900s said: "As long as we rule India, we are the greatest power in the world. If we lose it, we shall drop straight away to a third-rate Power."
Without a doubt, we were valuable to them. And this is exactly how it went down. The lesson to learn here is probably if they had treated India and Indians better then the empire may have lasted longer. Today they are a third rate power and they have themselves to blame.
We were extremely valuable to the Brits. Decolonization was one of the things agreed to in the wartime conferences because of World Wars. Anyway, as I stated below, I highly respect the freedom fighters of India and the sacrifices they made, but I very much doubt if the UK were at full power in the 40s, that they would have given up on us so readily.
No empire became great without the approval and participation of its peoples. Indians demanded full freedom in return for helping the british while they only agreed for dominion status. Even then, UK understood it would be impossible to hold on to India after the war, when 2 million Indian soldiers returned home while the civil disobedience movement had already clipped their wings. That was just the reality, just like how when the british entered India the mughals weren't at full force but in fact declining and the marathas weren't a full force either, but had just gained control over most of India. This feud left a huge vacuum in large swathes of the region, but it didn't happen just like that but after intense warring for decades. In fact, the whole islamic occupation was a centuries-long war so I don't see your point about war being alien to India or the local populations not having fought back. The british gained control because they exploited this ideological feud but it was not possible without local support. In fact, most of the soldiers that did the conquering across India were other Indians. Apart from that, I don't think it was possible for britain to win the war without Indian contribution and support and the price to pay for their own freedom, was to give us ours. It was a fair trade IMO, and it united us as Indians. Otherwise, we may have been a set of warring kingdoms again after the british left. Instead, we chose democracy and a social revolution. It's nothing to be ashamed of.
Keep in mind the West became "tolerant" post WW2. Before that, they had no moral obligation to give a shit about us and if we rebelled, it would have been Jallianwala Bagh 2.0.
True, but they were incredibly susceptible to criticism as they masqueraded as "civilized", while we were demonized. Gandhi was the perfect nemesis against that propaganda. The empire knew how to deal with someone who wielded a gun, just throw enough Indians under the bus and they would eventually win. What they did not know, is how to deal with someone without a gun. They hated gandhi and his guts. The man who stood up against the entire might of the empire and exposed their hypocrisy once and for all. He did it and asked to be arrested, and millions stood behind him. How do they kill the ideology without being equated to the nazis? They didn't have an answer to that.