Phones 30% to 50% larger would be disastrous. Uncomfortable, just too big. I think the way phones are now is about right. Still a bit too large to basically disappear in your pocket, but small enough to not be annoying.
It's not about fashion. Making phones larger would be a stupid idea indeed.
i disagree, my nokia 3210 was 100% thicker than my galaxy s2, but it was still comfortable to carry in my jeans pocket. i bought the extended battery for the galaxy s2, but would still buy a larger one if i would find one that provides the same confidence that the original Samsung one does.
It's not about fashion. Making phones larger would be a stupid idea indeed.