I think Obsidian just reads the file, so never faces a conflict. If there’s an edit in progress at the very moment it is changed elsewhere, I’m pretty sure the edit won’t be saved at the same time as open document is updated - it will update one before the other.
Google sync can’t always be instantaneous and will save conflicting copies; probably a minor issue as long as the conflicted copies are picked up quickly.
In general, I’d expect it would only be an issue where Google Sync was delayed (eg internet down) or two people were editing the same file.