Oppo Find N has an idea ... small expandable screen ... but FOLD is NOT the way forward.
I still see all foldable phones as communicators, like the Nokia communicator series from the 9000 (The Saint ft Val Kilmer) to the last model the E90. Every add or person that shows off a foldable online is basically copying what a 'fold' can do just like those communicators. Sure what you can do is modernized, but same basic movements with no physical keyboard, better internals and a screen that'll crack MUCH sooner than those fold tests can attest to.
Rollable is the way forward. Give me a 6.7" rolled out screen in the size of a iPhone 12/13 mini with incredible battery life, camera's, video recording and editing natively With iOS from Apple and I'll take a VERY hard look.
Until thin it's iPhone and nothing else.