I realised that I first noticed this because of another issue:
The button in the email notification (when there's a reply) will only lead to the first page of the thread, not the latest reply. When on my mobile, I'm happy to click on the button, but then I need to scroll down to find the last page to see the latest replies. Rotating to landscape view is a bit unwieldy when using the phone with one hand and hanging onto the grab handle on a train with the other.
Note: I deal with user interface design in my daily work, so more sensitive in this regard. But I also understand sometimes the solution can be a hassle to implement technically, so just throwing it out.