Total extinction of any dominant species is really hard. Very few post-apocalyptic settings suggest a full extinction and usually show some thousands of survivors struggling with the new norm. Humans in particular are very adaptable so thorough killing all 8 billion of us would be difficult no matter the scenario. I think only the Sun can do that and that's assuming we fail to find an exit strategy 5 billion years in (we're less than a thousandth of a percent into humanity if we measure on that scale).

As such, I'd say "extinction" is more of a colloquial use of "Massive point in history that kills off billions in short order".