Gah. The metaphor of calling screen area "screen real estate" has always been a pet peeve of mine but this "20 vertical pixels of virtual real estate" has me simultaneously impressed and horrified. Why not just "20 vertical pixels"?
I guess they are meant to color up speech / break monotony, but it gets irritating when metaphors are overused and nobody just says "battery", so in the end, just using the boring regular word feels more refreshing. Similarly for articles that keep overuse words like "whopping" instead of usual formal words (to appear more friendly, I guess), or infallibly say "invest" for everything rather than just "buy".
Empirically (I've done the comparison), desktop browser UIs have been growing in vertical screen occupation since Netscape Navigator 2 quite continuously, including the most recent versions, while reducing the amount of information and control provided by the interface. (That is, tabs introduced a new demand of some legitimacy. – However, another vertically stacked horizontal bar isn't the single imaginable solution to the problem. Previously, there had been sidebars with extracted link lists, we can do it for bookmarks and reading lists… We're even better at scanning vertical lists. There's quite some dogma involved. Arguably, a horizontal tab list shouldn't exceed 5 items.)