I have been using Obsidian as the app of choice for Personal Knowledge Management for the last two years. These are reasons you should too.
1. Notes captured using Markdown. Obsidian uses Markdown which allows the notes to be easily moved to another product or used by another app
2. Free syncing Obsidian lets users sync files via iCloud and other online drives and paid services. For example, this allows my notes to be synced across my Apple ecosystem.
3. Great community There are many Obsidian content creators and an online forum to learn from. This helps to discover new workflows and resolve issues.
4. Community Plugins Many community plugins are available for users within Obsidian. This helps me customise my workflow the way I want.
5. The Obsidian app is available on most OS and mobile devices. It allows me access to my notes when I need them.
6. Offline mode - Obsidian works offline when I want to use it without internet access