Our ancestors may have almost gone extinct 900M years ago. Some researchers looking at genetic data believe we were down to 1280 individuals [1].

Those were pre-human ancestors, but humans aren't special, we are just animals that are more destructive than any species that came before us.

Hubris will likely play a large role in any possible future human extinction event. E.g., doing nothing to curb climate change because we are "smart" and invincible and/or god(s) wouldn't allow things to get that bad, a deadly pathogen develops resistance to all antibiotics because of free-feeding antibiotics in factory farming animal flesh, we use nuclear weapons in conflict X believing it will not escalate (George "Baby" Bush, "I want nuclear weapons I can use" [actual quote]), a pathogen intentionally developed to both spread quickly and be extremely deadly (because we can), that somehow... "no one could ever foresee the possibility..." escaped the lab-- or maybe it will be a large meteor impact wiping out humans (and other large animals) across the globe like a kid stomping on an ant hill.

[1] https://www.scientificamerican.com/article/human-ancestors-n...