0: https://en.wikipedia.org/wiki/T9_(predictive_text)

It could be nostalgia, but I was pretty quick and generally accurate sending short messages.

Not sure I would want to type a document on T9.

Actual Keyboard >>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Touch screen typing >>>>>>> T9

You could literally type the message without taking the phone out of the pocket because it was extremely predictable and you knew the menu structure by the gut.

I updated to ios17 excited about the new transformer model, and it still predicts absolute BS words I’ve never used in my life.

I definitely remember typing working better on my iPhone 5 which was 20% smaller so I don’t know what’s gone wrong, but it’s gone really wrong and the fixes also suck.

Bonus points for e-ink-based keys.

Edit: Realistically I’d be surprised if something like this doesn’t already exist.

What about an updated BlackBerry Torch 9800?

Some of the immediate things that came to mind were making a case that integrates the phone with the keyboard; and a small battery to extend the life of the phone since the keyboard adds to the formfactor anyway.

Bonus points if this creates a market for a small phone again (iphone 12 user here).

I have seen people type blazingly fast on touchscreen phones though, albeit I didn't run error stats on their output. I accept that I may lack some skills needed to become better at this, but seeing others highlighting that this is a problem to them is not surprising to me, based on anecdotal evidence.

E.g., I knew someone who added to his email signature a permanent apology for typing errors giving the justification that he was typing on a touchscreen device.

All in all, I agree that the problem is real, and havging had experience with a working solution (physical keyboard) I wonder why there appears to be no business case today for such devices.