I can't see myself paying for foldables, but I think they are incredibly neat. I spend a ton of time on my phone, and the idea that the screen could get much bigger really tempts!

That said, I really wonder if this could be a shark jump move. I think one of iOS app's biggest wins is that developers have a relatively narrow set of form factors to target, that making bespoke interface layouts is the obvious choice & that that really allows careful crafting. I'm overselling this case a bit, but it feels like Apple is saying: ok, now make your apps responsive. Add more. Some folks will figure out each layout nicely, but I feel like in many cases, the responsive layouts are going to be less well crafted, not have such thought out intracacies.

I love responsiveness, but it generally pushes layout complexity down, requires simpler / plainer design languages, in my view. This pushes away from bespoke careful craft, and towards mechanized systems, and there's some design loss in this push.