I used to own a Fold 4 and it's a wonderful device, I really loved it (mostly the multitasking, stylus support, small outer screen for one-handed use). Unfortunately, the design is truly fragile and I sold mine after I got it back from the repair shop for the second time (and got a boring iPhone). I truly hope newer generations will be better and I can purchase one that will last at least 3-4 years.

From second hand experience (I’ve never owned one but my cousin loves foldables), they’re probably more reliable than an unadorned iphone. Folding means the screen isn’t fully exposed.

The major advantage of the iPhone is that its ecosystem of cases means you can get some pretty high quality cases that can make it actually protected.

I really like my Surface Duo for exactly that reason, folding it hides the screens. The device dimensions definitely aren't for everyone, but having the option for a larger device and the usability of two screens really is pretty handy.

The Duo has its own faults though, the body around the charging port is particularly fragile due to how thin they made the device.

Your intuition about screen fragility is right. I recently switched from a Samsung Flip 4 to a non-folding Pixel 8. While I liked the idea of it, in practice it was pretty chunky (twice the thickness of a normal phone when folded, too tall for my pockets when unfolded), and I damaged the screen twice in a year via normal use.