I think you're misunderstanding, or something. It isn't up for debate whether 3 cameras is more valuable than 2.
You can, however, decide whether that offering is acceptable to you for what you're paying and what else you might be getting with that purchase. I happily went from a 16 Pro Max to an iPhone Air last year. I was willing to trade 2 cameras, some battery life, and better speakers for the thin and light design.
But the iPhone Air is no where near the level of compromise that we're about to see with the foldable. The iPhone Air has a specifically desirable form factor (thin, light). The iPhone Fold appears to have an objectionable form factor (short fat, thick and heavy while folded). And replacing Face ID with Side Button Touch ID is perhaps the biggest downgrade in the history of iPhone. If it were under-display Touch ID...maybe it could be tolerable...it would still be a downgrade, but wouldn't be as bad of a UX as the side button is. But that isn't what's happening. And the price looks to be astronomical. All of this is to achieve ONE thing...the ability to unfold it into a device that's bigger than a Pro Max, but smaller than an iPad mini.
I'm not a hater on the foldable concept. I think it's neat. But I'm also realistic and not delusional. And I have a hard time seeing how 1 single benefit (unfolding it to a larger size) is worth ALL of those compromises in order to achieve it.