Not with a Bang, but a Whimper

A soft apocalypse with Nature taking back what was its, and what happens after.
The death of Humanity, or rather the replacement, the evolution to something other. Dwarvenkin, Elfinkin and others, those mistaken for nature spirits, and the oldest, as Gods.

(Started with a prompt, "The apocalypse, but it's nature reclaiming the Earth. The world is not becoming destroyed, but rather reborn.")