What I am looking for in a smartphone

Nüjtag asked me a very simple question on Mastodon which is not that simple to answer. What am I looking for in smartphone?

What I actually want is what will likely never exist. An iPhone Mini slightly larger than the current one which runs macOS when docked. With support for two ProDisplay XDRs please. At this point it is likely not a hardware limitation, but simply Apple making sure they continue to sell Macs.

I tried Android phones and do not like them. The integration into the Apple ecosystem iOS provides is a strong selling point. I barely use apps, I read books, answer emails, browse the web and occasionally turn on climate control on my car. Sometimes I take a picture of my dog - any camera past the iPhone X does not make a difference, I suck at taking pictures.

I wanted to love the iPhone Mini. But the battery did not hold up well enough for a full day of use. The screen was too small for any long form reading. The keyboard was a bit too small to comfortably type on.

My daily driver is an iPhone Pro Max. Comfortable to use for everything I do - read and write. I would prefer a foldable (one device instead of two) like the Z Fold, but Apple takes it time and worst case they will release a Razr style phone to not cannibalise iPad sales.

So what I am looking for in a phone can be summarised in a few points. Great looking display. As large as possible while it still fits in my pants pocket. iOS. As locked down as possible so I do not have to maintain yet another computer.