In Obsidian, tags and notes are not treated the same way. Notably, tags cannot have extra data assigned to them. This causes the following problems:

• The tag cannot be defined or clarified.
• Tags cannot be related to each other.

For these reasons, tags should be used only for ephemeral pieces of data such as statuses (read, todo, someday, athome). If I am about to make a tag that represents a topic, I should use a page instead.

This also falls in line more closely with zettelkasten, which has more interest in linking similar topics together so you can make new connections and discoveries.

Source: forum.obsidian.md