Have you used one? Is it really better?
Putting aside the biggest issue which is a creased and more fragile screen, I’m not really convinced it’s a better experience. Having more real estate for movies seems useful, but it’s otherwise difficult to type/hold/tap on such a large screen without a full commitment to tablet usage (which often includes a stand). I’m also not really sure how often I’d use the larger format.
The flagship foldables have two screens. A screen on the front that’s a full sized screen just like any other smart phone screen of the last 10 years.
But you can then fold the phone open to get access to that wider screen.
So you get the best of both worlds, a normal phone handset for one handed action. But a larger screen for when you want something that’s a little more “tablet” like.