It isn't more important than anything else when you're poor.
A poor person's highest priorities are keeping a roof over their heads, having food, heat, light and getting to the places (work, job centre) that enables them to get the money that achieves that.
It isn't more important than anything else when you're sick.
A sick person's highest priorities are getting treatment, and managing the symptoms so that they can have food, heat, light and getting to the places (work, job centre, hospital, pharmacy, physio) that enables them to get access to the professionals and the money that achieves that.
They're talking about survival of the planet. The planet will be fine, bar an asteroid strike, a megavolcano eruption or three or being cleared for a interstellar bypass by a pan galactic race of civil servants with a penchant for poetry. The current inhabitants as a whole, not so much. But when somebody is at the sharp end of feeding, housing and clothing themselves, that day to day existence is their personal survival - and that takes priority.
XR come across as self appointed white saviours. XR are negatively affecting the poorest people in society whilst, quite frankly, demonstrating they have significant personal economic and physical security. They aren't on the bones of their arse, trying to make ends meet and wondering whether they'll still have a job when they finally get to work because somebody is physically preventing them from getting there. They've got a day off, they've already covered their rent/mortgage/food/clothes/face paint and costumes budget for the month. Their physical and material needs are already met - and they are going on to prevent others from meeting their own needs.
If I have enough money to cover my rent, heat, light, council tax, travel to work, work clothes/shoes and medical treatment (all of which are non-negotiable), I will make decisions which attempt to minimise my environmental impact, but if my choice is pay this month's rent or not, then I am not going to be spending seventy quid on a reusable water bottle and telling work I'm not coming in on Friday because I'm going to be glueing myself to a Tube with a tube of cyanoacrylate which isn't in the slightest bit environmentally friendly and preventing thousands of other poor people from being able to pay for their rent, heat, light and food this month.