I'm glad to see someone else acknowledge this. I get "ok boomer" responses, or people looking at me like I'm growing a second face on my ass. Reactions are even worse than when you mention how shitty Word is as a text editor or word processor.
Structural editing in Lisps is a great convenience -- you manipulate expressions rather than characters.
Schemoid for Android is an admirable example.
Autocompletion based on my previous behaviors would be great, too: If I just googled “The Shining” in Android Chrome then open the Netflix app, Android should know to autofill the Netflix search bar with the completion (and select it, for easy deletion).
As phones are so big these days they require two hands anyway, I reminiscence of Palm Pre/webOS hold-below-the-screen-and-swipe-left-and-right to select exactly the right spot quickly and precisely. I don't remember the rest of the gestures, but at least I don't remember it being as frustrating as Android.
Nokia N9 (Maemo/Meego) also had a few interesting things, as did Ubuntu Touch.
I applaud any research into this though I can't imagine how it will ever beat physical keyboards (other than mind-reading).