It's obviously multifactorial, and I do not diminish Gandhi's efforts, but it would be hard to ignore Britain's diminished capabilities after WW2 as having a role in Britain letting go of India.

They simply had no capacity to control a country like India on the other side of the world in their state at the end of WW2, so might as well save as much face while they can.

Not just a question of capacity. The British Empire almost fell to Hitler's ambitions and while Great Britain was never invaded it definitely looked a lot weaker than what it was supposed to. This meant that the British Empire was far from invincible and definitely led the path to decolonisation.

There were also violent protests in India.

It does seem like opposing nonviolent and violent factions who reject each other works better than just one.

Northern Ireland, Malcolm X/MLK, etc.

Interesting point of view, never thought about the irish liberation, even though it was a recent development.

My opinion is that the fear of marxism permeating the civil right movement (especially the BPP) and starting to reach the Latino and disfavored white people (the "rainbow movement" if i remember correctly) did strike fear into the US government (hence the assassination of Fred Hampton, who really started this). This fear allowed to Civil right movement to be successful, because ethnic tension, while useful to exploit a minority, is not worth the danger to the social order.