I actually agree wholeheartedly. Apple's devices are the apex of form following function, which is why their form advances so rarely: the functionality of the iPhone changes so little from year-to-year, that Apple doesn't really need to re-engineer much. Hell, the iPhone 12 is just a redux of the iPhone 5 footprint, an anachronism that's yet another great example of form meandering while function stagnates. The deficiencies in our current devices are clear: they're centralized, non-extensible, and exceptionally difficult to fix when they break. Apple profits off all three of those markets, so I have little faith that they intend to change anything there soon.
> Contrast that to a competing product like the ASUS ROG Phone
Don't make me (or Tim Cook, for that matter) laugh. The iPhone doesn't compete with the ROG Phone: they're ostentatiously different products. One is a gaming phone, the other is an iPhone. You're comparing a dune-buggy to a Ford Fiesta, which you're welcome to do, but will sway very few of their respective audiences.
In the iPhone or iMac, what's on the screen is what is important. Nothing else is important, so it's not there. One of Rams' principles: "Good design is as little design as possible."
Contrast that to a competing product like the ASUS ROG Phone: RGB lights, not-strictly-necessary cosmetic vents, asymmetrical lines, printed design patterns. Now THAT is a product that would make Dieter Rams throw up in his mouth!