My own carelessness. Dropped a (pretty new) phone yesterday while getting into the car. Screen has shattered a bit in both corners are there are cracks running between the two.
I find a case that I have to open means that I'm more likely to drop the phone when I open it. A glass screen protector, and a shock absorbing silicon skin, seem to mean I only ever have to replace the screen protector...and not very often. At less than fiver, it seems a no brainer to protect something worth 40 times as much.
It also means I dont much have to care about the design of the phone itself. All I see is the screen and the buttons.
No idea why someone would willingly introduce a point of mechanical failure in order to have something that doesn't fit in a pocket as well as a regular device.
I've been buying the same type of Android phone for two decades and fancied something different, is all. I actually quite like the smaller form when folded and the bigger screen when opened, but I'm far from convinced I'd buy another one.
Bit like Sean, I was probably swayed a little by nostalgia, having had flip-phones back in the day.
The only phone I ever really coveted was the Nokia 2112 or whatever it was called. The one from the first Matrix film that had a springloaded cover that slid open when you pressed a button.