@welstand I don’t think there is a one-size fits all solution here, it boils down to what you want to use those notes for. Personally, I don’t write/store notes in Zotero at all. Zotero is primarily a reference manager, it can store notes, yes, but they will be stored away in their database, inaccessible to anything else, not to mention that note-taking there is a bit painful. All those notes will be siloed into whatever reference you’ve attached it into instead of linked to your other ideas.
Obsidian is primarily a note-taking app! It makes it easy to link those “might be interesting” notes with other ideas or problems you might be working on right now! My exported notes go into a folder in my vault (this allows for easy filtering if you want to make clear distinctions). I only send things to my vault if I already have a) read them (and most likely annotated them), b) have a use for them (e.g. I’m probably reading this paper because it’s related to a project I’m working on. If a paper I read is not useful for that project, those notes don’t get extracted & exported).