I just searched for an example where replies to a post are shown with the post, here is one…
It has a dropdown box under it marked ‘2 Replies’ which if you click on it shows the replies.
Now, those two replies are in fact the next two posts in the thread which are already been shown.
I guess what the forum software is hiding the fact the post is a reply if it’s replying to the previous post?
Edit, actually, the first post in this thread is an example, and I’ve also just noticed the arrow Octoberon mentioned to ‘go to the quoted post’. Also, for quotes there’s also a downward pointing chevron for expanding quotes.