There’s nothing wrong with you not seeing a benefit, meaning you don’t have to use it. Maybe look at it from the perspective of asking yourself, “What problem do I need to solve?” and then see if Obsidian can do that for you.
You mention mind maps. I really like the Excalidraw plug-in. It is more of a generic drawing tool and not specifically for mind maps so it doesn’t have the bells and whistles of dedicated mind map applications. However, it’s good enough for me and the neat thing is you can embed links in the mind map which can then take you to notes, or whatever.