I had a Fold 2 for a test drive and now I do own a Surface Duo.
Why? Because I like tech and although I prefer iOS, iPhones became the devices that just work, but are boring.
The Fold 3 seems like a device for having one app at a time, but for multitasking I do prefer the Duo with its two seperate screens.
Using 2 apps on the Fold makes them kinda skinny and the keyboard gets in your way on both sides while typing.
I guess if Apple ever makes one (be it a folding device or a unit with 2 screens) will be the point that apps actually take advantage of these screens.
For now, they are just a niche with compatibility issues.
For every moment you are amazed by these phones, you wiill be hit with 2 moments where they get in your way.
It may needs Samsung to develop the tech and Apple to make it work - we will see.