I think it is intended. It only shows who the reply was for if someone else posted before.
If it’s only the same two people replying in turns it’s assumed they are naturaly replying to each other. And you can simply follow the thread.
But if someone is replying to a post that is not the latest one and a different user replied in the meantime this creates a new thread inside the topic withe the “jump to post” function on the reply and a “expand thread” function for the post people replied to.
If the conversation is uninterrupted (everyone simply replied to the latest post or the topic) this is not assumed to be needed.