If you are worried about an extra $100 a year in power costs, then you have no business owning any high end cards, you can't afford them.
Also, where are you getting NO 4k. It does fine in the majority of titles, and in the games that it doesn't, even the 1080ti is having a tough time having decent average frame rates, which means it is the title more so than the card.
You are also keep saying that it barely keeps up with the 1080, yet in most of the reviews, it is shown that it beats the 1080 in many of the benchmarked games, with some of them showing it between the 1080 and the 1080ti, game dependent of course.
Also, it was already stated, Not so sure about some of the numbers in the reviews, because even I on my ancient x58 overclocked xeon platform which sports pci-e 2.0, I am getting higher averages than reported with equal or better settings (when they are not testing on max settings) at 1440p. And I'm not benching with an over clocked 7700k at 4.8Ghz or higher.