@julian @thisismissem this is less to do with tree traversal or root nodes or whatever, and more to do with reading from the inbox. activities are supposed to be notifications (at least in theory!), so there's a difference between saying "hey btw i made some random post and you should introspect it if you want to know more" versus saying "i replied to a post, specifically your post".

unfortunately in practice, activities are not used as notifications, they are used as poor man's JSON-RPC.