Last time I looked, the aspect ratios for the unfolded screens were such that you didn’t actually get any more screen real estate than a normal smartphone so the kids analogy doesn’t make a ton of sense to me. For media it’s like you get the illusion of a bigger screen.
Doesn’t that “feeling” though kinda confirm that it’s an illusion of screen space when you can measure the diagonal image on a normal phone and see that it’s the same?