Similar, not the same
Obsidian is a lot like Notion, minus the databases, but it runs locally.
Notion’s better for highly dynamic stuff & project management stuff… but Obsidian may be better for PKM.
Notion PKM Wins:
- Sync is not a concern
- Colorization is easier & callouts look better
- One fewer tools to have to learn
- Can make links available to anyone without hassle
- Saved views on the Database are nice
Obsidian PKM Wins:
- Faster
- Local & durable
- The graph view is neat
- Excalidraw works great
- Link previews on hover
- More customizable
- Can interact with code and regular file system operations
Source
- first hand experience