I think the key to smartphone keyboards is something like Nintype, two-finger swiping. It's incredibly fast and doesn't require you to learn a completely new keyboard layout to succeed.

It's also a lot more comfortable for one-hand typing since you can do multiple swipes per word.

Funny that looking at their "number of touches" and "distance covered" checker, I've tried a few words and thinking in my head how it'd be in Nintype and it would score far better than Keybee.

Unfortunately I haven't seen anyone since Nintype (and the older Keymonk) to give it an attempt.

"Like a Blackberry," I red the headline and thought. Then I looked and thought, "I'm old."

Compare 1996's "FITALY":

"For the FITALY layout, we have obtained an average travel of 1.8, to be compared to an average travel of 3.2 for the QWERTY layout. (For prose, involving few numbers and symbols, the results are even better.)"

https://www.textware.com/fitaly/fitaly.htm

https://the-gadgeteer.com/1998/08/22/fitaly_review/

And closer to OP, "HexInput":

"Please use this idea! If you are a software developer, I urge you to consider adding this functionality to your product. My hope is that ten years from now, we won't have to laboriously tap out messages letter by letter, but instead will be able to zip them out quickly and efficiently with something like HexInput." -Sept2006

https://www.strout.net/info/ideas/hexinput.html

1996, 2006, 2026... Your turn?