But if you use Nested  or Flat View  then you dont see if theres been any new posts since you last read the thread, and need to read all posts in the thread completely through each time.

No...?

And unless the poster has  used the Quote button,  it can be hard to be sure specifically  which  post in the thread is being replied to.

I keep trying  other ways, but always return to my preferred Threaded view.

It may be just an indication fo what's important to one person compared to another.