https://www.inference.org.uk/dasher/
I've been thinking about it some more recently, as AI could assist with word completion, and augmenting it with some AI helpers could really improve things. And if the idea was extended.
Not wanting to sound like an able-ist snob, but interfacing with traditional computers with a keyboard is hard. And the interface is clumsy. Even touch devices and keyboards. My Mum could never use a computer, but she has worked out how to use a tablet and find videos on Youtube. I keep meaning to introduce her to voice input. As this would really benefit her.
Despite the huge tech leaps with smartphones and tablets and what not, I do feel there has been a huge regression in basic communication between people only exacerbated by the pandemic. There's knowledge available easily at people's fingertips and that's great, along with new channels of communication. But text based comms have retarded many people.