Yes, it is all too plausible that humans will encounter a massive mortality event. But neither conclusion follows.
The earth will not be fine because the worse humans do, the more severe the extinction event will be on the way down. Desperate people do much more environmental damage than comfortable ones, for instance, finding wood to burn for fuel. Ocean acidification, soil depletion, microplastic pollution, trace chemical distribution, these sort of things aren't going away when we do. A major extinction event depletes the earth for millions of years.
And humanity viewed *as a species* does not need saving because in the event of a major extinction, we are the most stubbornly adaptable species ever.
The most likely outcome of continuing collective human stupidity will be a great loss of human life, yes, but we will be the LAST vertebrate species to go utterly extinct, and one of the last species altogether, vertebrate or not. We are heading for a much depleted planet with a few people huddling in highly engineered environments, not some imagined return to Eden.
I am sorry to say this, but it is clearly the more likely outcome. I think people want to think otherwise because it helps them to deal with their terror and guilt. Alas, hoping for a return of the natural past after humanity is gone is not the right way to cope, because it is not going to happen.
Always remember that it's easier to Mars-form the earth than to terraform Mars.
