Comment by eviks

> Button instead of Ctrl+Z

This is rather different, this is ignorance, so button alternatives are helpful for ignorant users (although one of the reasons for such widespread ignorance is precisely because there isn't really much of a learning curve since interfaces don't actually teach you much if at all)

But for a lot of whitespace instead of content, what exactly does it teach new users? Consider the toolbar example, how would showing a new user 3 buttons (left, right, section name) help instead of showing 3 buttons with section name and a 4th partial text button with section name?

Also, gmail density mostly affects vertical density, the number of horizontal tabs doesn't change, so the control density doesn't change as much except for the left list of categories (but only if it's a big list otherwise it would still fit in sparse UI ), making this mostly an aesthetic choice (unless you often need to see a lot of emails in a list)