I can imagine it being useful as a page down key but without having to press the page down key on your keyboard? I prefer the gnome implementation as well but above all else I prefer people having the choice.
What I never understood about the “windows” implementation is if the page cut a line in half and you go down one page the line is still cut in half on the top of the page meaning you have to scroll around anyway.
I’m just back to buying Blu rays. To me it’s the safer option, you legally own your product and you can host everything you want yourself still. MakeMKV is a great tool.