What am I trying to do when designing an RP campaign

What do I try to do when designing an RP campaign in my home-brewed world? Obviously, to make the players have fun. However, the ways that can be done are infinite, so most of these things are just for myself.

First, I design with the gods in mind, top down. If I try to think like a god, and I try to think what I'd want to do with these mortals whose souls are in my hand, then I can come up with motivations that can drive years of gaming. It also helps that trying to think like a god helps me in my own spirituality...really! When I design a god that loves its 'children', how would I design that in such a way where the cause and effect world could still exist? In a similar way, how do I get over Epicurus' "Problem of Evil"? Envisioning ways that a loving D&D god could allow the world to exist in such a fashion helps me realize how it is so in this world.

Second, I take a page from Tolkien's book, in that I tend to treat my D&D homebrew world as a mythical world, whose heroes' great deeds are "just-so" stories for the world to shape its culture (especially language) around. Just as Gandalf described how the Old Took created the game of golf by lopping off a goblin head to have it fall down a gopher hole, so do adventures in my games answer the question, "Why is your world the way it is?" Each campaign I run in this world informs the next campaign. Just like great Greek heroes become constellations of stars, my D&D heroes become ascended gods themselves, and knowledge of these mortals who became representations of aspects of reality shapes the world's cultures.

An example: In this campaign, one of the major players is a powerful wizard called Hubrin. He will be where the word 'hubris' comes from, in this world. Common is an already established language in this world, but Common is not necessarily real world English, nor vice versa. Who is to say that the word for 'excessive self-pride' was even coined before this moment? There are a thousand arguments that could poke holes in this setup, so I leave the timeline vague. Myths do not have to line up perfectly. (See also: Comic Book Time.)

Lastly, more common sense: I try to make as many interconnections as possible. What ties two cities together? What happens when the hobgoblin cave next to town is cleared out? I try to create wide-spread consequences. These often point the way towards a new adventure very easily. They are also used to show the players how their actions have results, which adds to their sense of accomplishment.

I may add more aspects here later, but these are the main points I wanted to spell out.