It doesn't mean, if you obviously don't understand the requirement, that it's not important to many graphic designers in different fields.
Of course, it doesn't matter what the aspect ratio of the image and the display experience. That's what the simple function of adjusting vertically or horizontally is for. See a nice sample of video players.
But it's mostly about a lot of artists simply clicking and switching to fullscreen of their work. This way we have to laboriously download the output and open it in e.g. FastStone, ZPS, ACDSee and other media viewers.
The odd thing here is that the developers ignore the Win clients requirement and this feature is common in all competing editors. Why it's not in Aff Photo even after more than 3 years, I just don't understand.
And someone from Sherif, also out of courtesy, could respond here on this topic and give a relevant explanation. π³π₯Ίπ€