Is it possible that there's in some sense a unique "global optimum" of UI and/or aesthetic design (as opposed to just a bunch of equally good but very different designs), at least as far as is possible under the constraints of available technology and resources at any given time? I would guess probably not for aesthetics (too subjective), but it's reasonable IMO in at least some very minimal cases of UI design - e.g., the idea of using some kind of touchpad gesture to scroll on a laptop. If so, maybe that optimum should be considered a "public good" that no single entity should be allowed to monopolize (or, they could be allowed to monopolize it only for a certain period of time like in the pharmaceutical industry and/or forced to license it for a reasonable fee) - otherwise for all of eternity it's illegal for any other company to use the "best possible UI" in their competing product, and in the meantime the company that filed a patent for it could have stopped developing their product entirely.

Less abstractly, I think the author's point about the standardized "UI" for cars is a good one - society is better off, not worse off, as a result of companies copying each other in the auto industry. If you can drive one car you can drive them all (well...except for the automatic/manual thing). You don't need to spend three days relearning how to drive every time you rent a car. In the same way, society benefits a LOT from familiar UI design across different software companies - e.g., anyone who has ever used any mainstream desktop OS in the past 15 years or so can pretty quickly figure out the basics of any other mainstream desktop OS - they all have programs partitioned into "windows", have a "desktop" with "icons", etc. These UI elements all seem trivially obvious to us precisely because of copying, but there are certainly alternatives to all of them.