Someone made a nice comparison of what the iPhone fold displays will look like compared to other foldable devices. Although I’d definitely prefer a larger display, I do think they are making the right move with the aspect ratio and in the end, that could be more useful in day to day use than having a larger screen.
What will be very interesting is to see how the rest of the industry reacts. All of the Android phones have settled on tall narrow cover screens with more square internal displays. With Apple going a completely different route, I’m sure at least some of the competition will be adapting their designs.