This could be useful both on modern laptops and tablets/phones/e-ink devices.
When enabling the reader mode for web pages, it would be great to be able to "flip" pages instead of scrolling through a long text.
That action could be accomplished by pushing on a hardware button (page up, page down on laptops) or by tapping an on-screen icon or just on the left/right edge of the screen of a touchscreen device.
This feature of ebook reader apps and e-ink devices is very good to avoid eyes fatigue when reading for an extended period of time.