well, yeah, the news always exaggerates shit and no sane political leader would press the launch button on purpose. And, even in many "doomsday" scenarios humanity still lives. Whether that would be the case for a nuclear war, who knows.
Ideally something on the planetary scale happens. Meteor strike, supervolcano eruption, a solar flare or storm. Some of those are relatively undetectable in advance and could happen any day, and would hopefully destroy the human species. However, it's not worth banking our personal salvation on an apocalyptic doomsday event. We could kill ourselves easily if we really wanted, but painless/peaceful methods are difficult to access for many.