[squarefoot]

Large screens are more usable, small screens are more portable. There's no way to have both unless we completely rethink the mobile platform itself moving away from the dream of having one big clunky jack of all trades, but rather as a group of devices, all interconnected (mesh PAN + shared storage) and equipped with the hardware they need for the task, so that one small screen device is used as a phone, a bigger one to navigate, read bigger documents, watch movies etc, one even smaller one to shoot photos and videos, one to listen to music, record it etc.

[spurgu]

In my experience, having used smartphones since 2008 (Nokia N95, N900, then mostly Android since), I can confidently say that 4-5 inches is a sweet spot for usability/portability. Anything less than that becomes difficult to type on and larger than that obv improves readability but you can go up to 50 inches if you disregard portability and I haven't had a 5+ inch mobile that I haven't had problems with keeping put in my shorts pocket. And handling the phone with one hand gets increasingly more difficult when you go above 5. And I think I have slightly larger than average hands (good pianist fingers).

The idiocy is focusing on slim devices. Just make them a bit thicker if the chips/circuits don't fit otherwise (and increase battery life while at it).

And yeah this was more of a ramble, not directed at your post. But I agree. I already have an Amazfit Bip (~€60) with a 3-4 week battery life that I use solely to get notifications on my wrist instead of having to pick up my phone. A watch is completely usable for anything else than a passive reading device though (at least until speech-to-text or (some kind of) gestures makes leaps forward). If as you say the devices were more interconnected (Chromecast is a step in this direction, connecting screens/TV's) the form factor of one specific becomes less important.

But, since we don't have this now, why not give the consumer a choice? My main gripe is that everything is in the 5-6 range whereas a little while back (2-3 years?) you could find a broad range of smartphones between 4-6 inches. It's gone from 100/0 in <4" vs >4" to 0/100. I would be fine to even have 20/80.

/rant

[dTal]

My favorite Android phone ever was the Xperia Mini Pro sk17i - a 3-inch screen slider N900-alike. Despite its tiny portability, it was not difficult to type on at all, due to its hardware keyboard - in fact the keyboard is about 30% bigger than the onscreen keyboard in a portrait Galaxy S3. It was not the thinnest, but it was palm sized and palm shaped so the ergonomics were excellent. I miss it badly.

[jbboehr]

Conspiracy theory inbound: The size of the battery is precisely tuned such that after two years of degradation, it lasts less than a day (~16 hours), so people are driven to upgrade. All thickness "improvements" are incidental.