I’ve been using it to learn about/discuss/work on the same topic area for several years (since Obsidian’s first beta launch IIRC). Now I will regularly be writing up notes on a “new” topic and start tagging entities (or people/companies) and realize I already have some old notes on them. Then it’s easy to traverse the graph to find all sorts of adjacent context.

It just has a great balance of level of work required to add organization to your notes versus level of work required to leverage that organization.