I have the 13inch M4 iPad Pro, and the thinness is cool I guess, but I don’t really care. It wasn’t a major factor in my purchase, nor is it in my enjoyment (and it’s in a case anyway). Out of its case, it feels solid/rigid though, so if this ’iPhone Air’ is both thicker and smaller I wouldn’t have any concerns about ‘bendgate 2.0’.
I’ll be sticking with my 13 Mini for now, as Apple continue to fail to make a new iPhone that appeals to me. I’d love a new Mini (or smaller, like the OG SE, still the best iPhone for its time IMHO) but I fear the chances are… thin(!).