Foldable smartphones are still in their first development period, their prices are high and their technologies are somewhat rudimentary, so that there are few manufacturers, but Apple is preparing itself for the future, through prototypes and patents for a foldable iPhone.
Currently, Apple is testing the foldable screen, and the company is discussing several measurements such as the same 6.7 inches found in the Galaxy Z Flip. Imagine it would be a small foldable smartphone and when opened it would have the size iPhone 12 Pro Max.
We do not yet know the foldable screen technology that Apple will use, as foldable phones need a layer of plastic that is placed on top of the screen layers to allow for the flexibility of folding, instead of glass, and this plastic has a weaker resistance to scratches.
Or the company may use two screens and are placed next to some, such as the Surface Duo phone, which does not allow the idea of the extended screen to display pictures and videos on a comprehensive scale without interruption.
If Apple were able to take the advantages and pros of both methods, that is, one comprehensive and foldable extended screen, it would transform the idea of foldable phones into something usual and everyone would go to develop it.
Certainly, it is too early to judge whether Apple will launch such a phone in the first place, and if it happens, it will be in the coming years, pending further development and stability of technology.