The Philosopher
This is a genuinely close call now, and the honest answer is: it depends on what you're optimizing for, because Obsidian's recent additions close the gap without eliminating the underlying architectural differences between the two tools.
Where the case for Notion still holds:
Collaboration at scale. Notion's multiplayer editing, comments, mentions, and shared workspace permissions are mature and battle-tested for teams. Obsidian's sync is genuinely good for personal use and small-scale sharing, but Notion is built from the ground up for multi-person, cross-functional work—onboarding docs, wikis, shared roadmaps. If you need a non-technical team of ten people collaborating in real time with granular permissions, Notion's infrastructure is still ahead.
Structured data and relations. Bases brings database-like views to Obsidian, which is a big deal, but Notion's relational database model—linking databases together, rollups, formulas that reference across tables—is more developed. If your use case looks like a lightweight CRM, a project tracker with dependencies, or anything where you're relating structured records to each other, Notion's data model is more mature.
Polish and accessibility for non-technical users. Notion's UI is more approachable for people who don't want to think about markdown, plugins, or file systems. If you're rolling out a tool to a team where half the people don't want to learn a new mental model, Notion's lower floor matters more than Obsidian's higher ceiling.
Web-first, no-install access. Notion works identically in a browser with no local setup. Obsidian's local-first architecture is a feature for many, but it's friction for others—especially guests, clients, or occasional collaborators who just need to view or edit one page.
Templates, integrations, and API ecosystem. Notion's API and third-party integration ecosystem (Zapier, automation tools, embeds) is broader and more consumer-friendly than Obsidian's plugin-based extensibility, which still assumes some tolerance for tinkering.
Where the case for Notion has weakened:
If your use case is personal knowledge management, note-taking, or a small team comfortable with markdown, the previous reasons to pick Notion—cross-device sync and lightweight database views—are no longer differentiators. Obsidian now offers those plus local-first storage, markdown portability, and a vastly more mature plugin ecosystem for extending functionality Notion doesn't offer at all (graph views, spaced repetition, canvas, etc.).
The honest framing:
The decision isn't really "Bases + Sync vs. no Bases + Sync" anymore—it's "do you value collaborative, structured, web-first work (Notion) or do you value ownership, extensibility, and local-first files (Obsidian)?" Bases and sync removed feature-gap reasons to pay for Notion; they didn't remove architectural reasons. If you're a solo user or small technical team, I'd lean toward saying the case for paying for Notion has become genuinely weak. If you're managing team knowledge work with non-technical stakeholders, Notion's reasons to exist are mostly intact.