Surely XR's point is that it's too late for individual action, only rapid action at a governmental level across the world has any hope of addressing climate change.
Some of them believe we've probably already reached the point of no return.
Whatever you think of their methods there is a lot of thought behind it.
They are trying to enact rapid social change through non-violent means.
(And there is a lot of thought over how they define non-violent)
They are trying to get around 3.5% of the population on their side/mobilised because they think that's the tipping point towards achieving their goals.