I tend to believe people naturally think in graphical structures, not trees. It's sort of an impedance mismatch though because our physical world is tree based - you can't put an object in more than one container. So we're continually struggling to transition back and forth, to the point that we unnaturally try to force our thoughts into tree structures like outliners.
Trilium Notes[0] allows that. In fact I'm surprised that it's not mentioned here, because when I discovered it (via HN IIRC), it seemed to me that Trilium had already implemented everything I could have ever thought of for a note taking/personal knowledge management tool, and more.
100% correct. It pains me but restricting to a tree was a compromise I wanted to make. Why? Because visualising a graph in a concise way is difficult. The point of jumproot is to have very broad and deep document structures and visual graphs simply don't allow it (to my standards anyway).
I'm always on the lookout for a widget that allows me to display a large graph in a very dense way. Please let me know if you come across one.