[pjc50]

You could make a similar argument about the notch, because now the screen isn't even properly rectangular - but that didn't stop it taking off and even being added cosmetically to phones that don't require it.

Let's not forget that smartwatches are popular despite being square.

All sorts of things could be tried. The 16:9 screen that folds to 8:9 could be like the Motorola Razr? Or you could fold it on the other axis to produce something like the Nokia communicator?

Hell, why not have two folds? Popup book mechanics?

[nathcun]

Maybe my wording wasn't great, I didn't want to say the folding itself is a problem, the problem is that the aspect ratios of the two are dependent on each other, making unusual solutions like you mentioned necessary. Not that that's a bad thing, but it is something that will require some creativity that we don't need to consider normally.