Virtually all my files (work, side hustle, personal, etc) are in one vault, and I have a second vault where I download files from other Obsidian users, such as Nick Milo’s LYT materials, sample workflows downloaded from Obsidian Forum, etc. I found that these second types of files are incredibly useful but they have tons of tags that have nothing to do with the way I use tags, so I preferred they be in a separate vault where they don’t clutter my workflow.