I've been slowly (very very slowly) moving my worldbuilding and writing into Obsidian purely for the graph and the connections it can show. It's so handy for running home-brewed tabletop worlds where I want to know what NPC might be connected to what faction, and where they all live... it's truly wonderful. I have another friend who uses his for personal notes/project notes about programming concepts he learns. It's a very versatile little program!