I love the ability to quickly copy, paste, select-all, type special characters, etc., all without having to do anything complicated. It took me a little bit of time to get used to the layout, but now I type exactly what I want, as I want it, without any auto-correct or automation needed. I make few errors and love the whole way of doing it. QWERTY makes very little sense on such a small screen, but it's what people know.
Is it like retraining yourself to use Dvorak? Or more like learning the Palm strokes?
Took about two weeks of daily driving until it was no longer painful, then three months until I had matched Qwerty speed. So probably similar to your thumb-key experience.
I picked it up to a usable speed within two days, helped by the fact that I use a lot of technical terms that autocorrect used to dismantle, so the baseline was much worse.
Look — I don't know if it was on purpose, but I chuckled.
edit: I tried it and I already like it better.
https://entropicthoughts.com/rethinking-text-input-on-touchs...
I actually want to get around making something customisable. A keyboard that you will put whatever keys you want, wherever you want. iPhone is too small for a comfortable keyboard, otherwise.