Free Roam Research alternative

There are roughly 20-30 tools actively positioned as Roam alternatives, ranging from Obsidian and Logseq (free, open-source) to Notion, RemNote, and Athens. The market feels crowded but it's deceptively shallow—most alternatives are either markdown editors with backlink features bolted on, or they're free but stripped of the things power users actually need (bidirectional linking quality, graph visualization, plugin ecosystems, collaborative features). The real pain point isn't the free/paid binary; it's that "free Roam alternative" searchers are actually looking for three different things: a cheaper note-taking app, a second brain system without vendor lock-in, or a knowledge graph tool for research and writing. Most competitors optimize for one and fail at the others. The actual gap sits in tools that give you Roam's graph-thinking model without the $165/year price, while also nailing ease-of-use for non-technical users. Logseq and Obsidian own the technical segment; Notion owns the all-in-one segment. What's missing is a clean, intuitive, free tool specifically built for researchers, writers, and students who want networked thinking without the friction of learning Markdown or managing local files.