You're right, it's expensive and hard, so it's better to not do anything and... migrate all humanity onto space stations so we don't die with the earth, I guess is the alternative you're suggesting?
This is why climate scientists have been saying for a hundred years that we need to stop producing all this CO2, because we can't take it back. We can't just fix it. We can't just get back all the ice that's melted and keeps melting, we can't unthaw the permafrost. We can't stop all the methane and other climate gases that have been trapped under ice for millions of years from being released and making it even worse. We just can not do it.
We were warned, we ignored the warnings and now we're seeing the consequences.
If you look at a chart of historic temperature levels, pretty much every significant change on that chart corresponds to a mass extinction.
So yes, the earth does die. The earth has died many times before and it's currently happening again. The rock itself will still be here but us and pretty much everything else that lives here will be wiped out by climate change. The only question is how long it will take, and as you can see it's going fast.
This is not controversial, except for ignorant people who refuse to face the facts. This is what climate scientists have been warning us about for our entire lives.
Doesn't matter whether you believe it, it's happening.