I sometimes wonder if modal editing (like vim uses) might be a good approach for navigating/editing longform text on touch devices.
It does seem like a missed opportunity to have taken the keyboard/mouse approach and then transferred it to touch devices. Even the keyboard layout has no real advantage for two thumb typing on a screen.
Approaches that adapt the interface whilst leaning heavily on letter based inference could be interesting for one handed / single digit entry of letters. Something like dasher: https://www.inference.org.uk/dasher/dashersummary.html