Π Firefox, on the basis of which the release of Firefox 78 will be prepared, reworked version of the Reader Mode, the design of which is brought into line with the design elements . The most notable change was the replacement of the compact sidebar with a top bar with larger buttons and text labels. As The changes indicate the desire to make more visible the buttons for controlling fonts, calling the speech synthesizer and saving to the Pocket service. The conducted research showed that users lose sight of them and do not notice them (perhaps the lack of demand for buttons is explained not by the fact that they are not noticed, but by the fact that they are not needed).
Change already laptop users with wide screens, as the extra top bezel reduces the available vertical space, creates the need for additional scrolling, and reduces the amount of content that can fit on the screen. When scrolling down, the text labels disappear and the size of the panel decreases, which is distracting (a change in peripheral vision involuntarily forces the eye to move to the top). What's more, the new "Done" button is misleading and doesn't remove the panel, as you might think, but initiates exit from reader mode.
Source: opennet.ru