I mean, everything would seem to indicate that mitochondria were assimilated while our ancestors were still microbes themselves. But that aside, our species is the result of everything that happened prior to its appearance, including for example the Cretaceous–Paleogene extinction event. Arguing that we should not attempt to prevent such events (if we're able to) because it would evolutionarily benefit the survivors is suicidal.

There's nothing special about our species. If things had happened different would the species that would have been in our place (whatever that means) be better or worse by any metric one chooses? There's no point in wondering about that.