I once associated with a rather gifted, if not mentally disturbed coder who had taken it upon himself to create his own codebase.
Anyway, he had rather unique views on what people should and should not be allowed to do and allowed people to do pretty much whatever they wanted to do. He created, for testing purposes, several test muds just to perfect 1 piece of code or another. For instance, he created a space mud that utilized the x, y, and z axis so that he could perfect his 3d fighting code...
Of the many things that went on in that MUD, one of them was world building. You found a planet, inhabited it, funded it, and reaped funds from it from trade and the like. One of the really nice abilities was the fact that you could create your own world out of the planet you landed on. You had a limited number of "spaces" you could use, but you could shape that planet to your own liking by going on to the surface of the planet and forging your path across the outside surface. Once you had a planet that you liked, you could then set the room descriptions for each and every "room" on that planet. You could create your own wilderness and set the room flags to wilderness so that certain things happened there, such as wild game or plant growth. You could build rooms of a certain type that took a little while to finish and be populated with shopkeepers or whatever was appropriate, such as an inn, or a food shop, or a casino. They all belonged to you as well so you could adjust or completely redo the room descriptions as you saw fit.
Another thing that was implemented on that particular mud was the building of items... you had to dig for ore or trade for it and then you could craft items of certain types, only if you had a proficiency in that, which was something you decided upon character creation... which forced you to deal with other players. You could be the best blacksmith in the world but have no leatherworking skills, etc.
I think my entire point (I've lost it, it's what happens when you get old and are doing too many things at one time) is that there is a lot of freedom that could be given to players to do many things if someone would take the time to sit down and write the code. I know personally I loved the ability to change the room descriptions, and the ability to control my environment that belonged to me on there. So it would be worthwhile to come up with a plan and some code for stuff like this, even if it starts in small steps.