When I played a lot as a kid/teen I spent a lot of time thinking about campaign worlds. I drew up new ones habitually, devoured many of the 2ed campaign worlds and I even bought the first version of Campaign Cartographer and spent a lot of time learning how to use it. Now I mostly play in vaguely defined worlds with maybe a small region mapped - or maybe not. This works fine for the most part.
I have been thinking though that their might be advantage in spending some time creating a more detailed campaign world. A world that I could reuse across campaigns. I wouldn't start at a high level of detail, but at least I could put all of my campaign design efforts in one direction. As I add things for different games they could all just go on the map somewhere.
Now let's see if I really start or if this stays in the realm of imagination.