Biodiversity loss and the loss of all life are two completely different things. Biodiversity loss and mass extinction has happened numerous times in the history of life. The one caused by us isn’t even the most significant one. We’re not even the most significant group of organisms that has caused mass extinctions, that probably goes to the myriad prehistoric species that caused the initial rapid rise in water and atmospheric oxygen levels which ended up killing most organisms including most of themselves (whom we owe our own existence to by the way, when species die out other species fill their place). Obviously not saying that we shouldn’t do something about our ecological impact, but the idea that unless WE fix ourselves all life is doomed is just not true and is a pretty “white knight” attitude. The reason we should clean up our act is for our own survival, we shouldn’t delude ourselves that all life on Earth is counting on us.