You can now sell vision to smaller alliances. Many guilds will pay real in-game gold (or resources) for you to scout the Obsidian Keep for them because you have the map unlocked and they do not. Become a mercenary cartographer.

When a player has access to the entire array of maps, they are forced to diversify their military compositions rather than relying on a single "doom stack" build that worked on the introductory stages. 4. The Psychology of Map Completion in Indie Strategy The desire to achieve "all maps unlocked" in Swordfall: Kingdoms