Comment by bc_programming

I think elements like scrollbars remaining visible serve a useful purpose of their own. I don't just mean scrollbars in this case depicting the location in the scroll, either, but instead offering a fully predictable interface that looks the same and doesn't depend on state. Elements like scrollbars only appearing when needed- expanding when you hover near them, for example, removes some of the predictability of the interface. If you have elements all over a UI that only appear "when needed" it starts to become a bit of a circus show, IMO; ribbons or toolbars or menus that only appear when you press alt or hover near the top of a window; scrollbars that only appear when you either scroll or move the mouse near the scroll elevator area, etc. It's some of the same push that has removed titlebars from desktop UI. Programs like Chrome spearheaded effectively taking over that area, because it's a "waste of screen space", But it's not, that screen space was used for a predictable, known UI element that used to be fully expected on all desktop UI Window elements. It's sort of like how we have with writing a predictable convention of words on a page to have margins on the left and right. If that followed the way UX has gone we'd have dismissed page margins as "wasted space" and all text would have 0" margins and run all the way to the edges of the page and we'd pat ourselves on the back for "using page real estate" more effectively.