It takes time to build a world.
The first design is not difficult. I know what to place where and when. But the sub-plots can get complicated. My characters are not all born here. They or their parents come from different places, and carry a different world within them.
How do these sub-worlds react to one another will decide the future.
And then that wide universe out there … looks so disinterested right now. They may not want any transgression of boundary lines, or my denizens getting too adventurous.
I don’t know what secret weapons they hold. Who wrote their stories?
There comes a time when the author has to let go of the characters, and let them decide what to do. They may choose the apocalypse, or intersections with other worlds.