They really need to add random areas to the open world. Like you explorer and you find a ??? item and examine it, and it's either nothing, a small den, a huge cavern etc. You then zone into it (like a small portal) and explore and entirely random generated area and anyone else that comes to the same area can zone into the same portal you went into (meaning their shared).

Each area in the game should have it's own random generator seed so that the random areas look like they belong to the zone they were found in.