"The asteroid that caused the Cretaceous–Paleogene extinction event was also just a blip on Earth’s history, it did however succeed in making life on earth miserable for a few thousand years, wiping out 75% of the all the species in the process."

Sure, but that leaves a heaping helping of the remaining 25% to carry on to eventually repopulate the planet with more glorious life. It's happened before, it'll happen again, and whether we're the reason or the victim doesn't really matter. Life finds a way, with or without humans.