If you would like to imagine how a Galaxy Z Flip paired with iOS could look, then you should have a look here. While a foldable iPhone is probably a long way off yet, an iPhone Flip, or an iPhone 12 Flip, is already a reality. Digitally at least, anyway.
https://www.notebookcheck.net/Foldable-Apple-iPhone-12-Flip-Concept-video-inspires.455316.0.html