Board Thread:Support Requests - Community Management/@comment-28694584-20201022020852/@comment-168424-20201022021924

So, for stuff that you don't want others to be able to edit should be created as blogs (intended to only be editable by the author) and not articles. So, if you do become an admin, you should suggest that to prevent the problem you're complaining about.

You can lock pages to prevent anonymous users (is that what you mean by guest users), but it won't prevent other registered users from editing. You can't lock an article page to be editable by a particular regular user.