The first touch devices might've been around 3.5-4" (just guessing here) but they've since then been constantly growing to where 6" is nowadays considered normal. How far can you going up in size? It's definitely not comparable to finding the size of a seat, as a phone's "right size" depends on how you intend to use it. There are hundreds of phone models on the market but they all seem to revolve around price points (and hence features/specs). Why not expand the range size-wise as well while at it?
I have fairly large hands and I don't mind manhandling a 6" "phone" but I simply do not want to carry one in my pocket. I can't imagine I'm alone on this. Largest phone I've ever had was 5.5" and that one constantly fell out of my shorts pocket when sitting down and now with the 4" iPhone SE I've grown rather accustomed to the form factor and am willing to trade off usability (more difficult, precise typing required) for it.
And then you have people with small hands.
Edit: Easy one-handed usage is also important to me.
I beg to differ! Airlines have slowly crammed in more and more seats for years.
"Less legroom is now the industry norm. In the early-2000s, rows in economy used to be 34 inches (86 centimeters) to 35 inches apart; now 30 to 31 inches is typical, though 28 inches can be found on short flights, according to Washington D.C.-based advocacy group Flyers Rights. Seats have narrowed, too, from about 18.5 inches to 17 inches on average."
Availability of smaller cars keeps going down (Honda Fit dropped in Canada, Toyota Prius C gone, etc.)
[1]: https://www.teoalida.com/cardatabase/images/Car-Classes.png
Airlines I've flown with Over the last few years haven’t been very accommodating...
Besides, even having the option to pay for extra legroom is what I'm missing altogether from the mobile phone market. Do you see my point? At least you have the option when it comes to legroom. I don't have any sub 5" options when it comes to Android phones, even though I would be prepared to pay extra for it.
I don't like having to pay more money because I was born a different size. Not to mention you are usually paying more than other customers for the added responsibility of accepting to help in case of an emergency.
This applies whether you're homosexual, heterosexual, or both.
Oh, and statistically you make more money as well. But you're less comfortable on airplanes, and Asian minibuses, so it's impossible to know if it's a net benefit or not...
If you eat more than the average person do you also expect grocery stores to give you extra food at no extra cost?
But you're fine with paying extra for more screen estate on your phone?
I'd gladly pay less - or more (I don't care either way, I just want the option!) - for a smaller footprint phone.
That said, this boat has been sailed. Modern apps won't work on tiny screens because their developers optimize for large screens, so it's a pointless desire.
One would think that you'd test the whole iPhone range when developing, since it's actually doable (compared to the Android landscape with infinite resolutions) but no.
I'm not blaming Apple for that though.
It wouldn’t be so bad if the phone had a window manager and you could keep everything you wanted in a corner (although the iPhone 7 digitizer feels less accurate than the SE was so maybe that wouldn’t work so well.)
These options are available, there’s nothing for people who want to have a hand sized phone.