I just would love to share the fact that from someone who tried so many times to make a deep and complex story. And expected the players to react in kind. It is so much more fun and enjoyable when you keep the story simple along with the plot. You don't have to stress as much if your players don't go where you want them to or not make the choices you wanted. It's so freeing and you get more laughs when the story is written by the players through their reaction to something happening to the world they live in.

I believe that the complexity can be achieved by building on the simplicity. Oftentimes, it doesn't have to be deep or all of it being connected because not every tables the same and most players are just there to have a good time not have a deep philosophical conversation about the meaning of life. We should be "playing" D&D not winning it.

So as a DM, remember to have fun and don't stress too much about the story. Your players will basically write it for you.