I think the whole framing of climate issues as "saving the planet" is misguided. Yes, the planet will remain livable pretty much no matter what. The threat of climate change isn't the literal destruction of the planet, or even the literal extinction of humanity. Rather it's such severe changes to the planet's biosphere that human civilization would be threatened.
Potential climate catastrophe scenarios where rapidly rising sea levels submerge many inhabited areas and various knock-on effects disrupt the food chain, even in those scenarios the planet is fine on geological timescales. What's not fine is human civilization, on human timescales. And I think this is what gets inadvertently hidden behind planet-saving rhetoric. If the worst case scenarios are "only" about billions of people dying due to resource scarcity and conflicts over said resources, this is something to be avoided.
I see a parallel with global nuclear war. Such a war would probably not end the species, there would be groups of survivors here and there. But human civilization as we know it would be over, with the global population being back to what it was in the hunter-gatherer era.
Isn't even that dramatically overstated?
If sea levels rise significantly faster than over the last century, this seems likely to cause economic disruption, rather than threatening human civilization.
Even when we look at knock-on effects and food security, it seems very unlikely to threaten wealthy, developed countries with diversified food supply.
It is still going to disproportionately affect developing countries that are already struggling.