It really is not as simple as that and comparisons with bbPress are completely spurious. If it were that simple - we would have done this a long time ago. 

It is not just a matter of a new post or new topic. You are currently posting as a member with restricted access. Because of the sophisticated nature of our permissions system what you see on this page will differ from what an active member will see, from what a non-member will see and from what an admin will see. As an admin, for example, I see two extra forums available on group view.

So - the quick-link drop-downs will be different. So will the new/unread posts list. So will, for example, the buttons at the top of each post. Dependent upon what permissions any one, particular user has been granted.

And then there are the little, less significant things like how long ago a post was made. On a not very busy forum - or on a slow day - a post could continually show as being posted a minute ago.

I could go on but I think you probably get the picture!

What I should add is that we do try and cache certain data internally wherever possible and are always on the lookout for any way we can add more caching. It is a high priority.