My understanding is that voice interfacing is already the most common way to interact with a smartphone in China. Chinese (and other non-alphabetic languages) are notoriously tedious to type, and all sorts of keyboards have been invented to make it easier, but they all have a learning curve. Instead, it is far simpler to simply use voice recognition.

Cliff Kuang and Robert Fabricant's User Friendly is a really good book for learning about state of the art UI / UX design and the current trends that are likely to determine what our computer interfaces will look like in 2025 - 2030.

https://fuchsia.googlesource.com/ , Fuchsia - Wikipedia - Another really interesting project. This is Google's new operating system they are building from scratch to replace Android, ChromeOS, Windows, and perhaps even server Linux. Fuchsia is being built from the ground up as a sort of one OS to rule them all, and with that they are replacing the traditional desktop metaphor with a conversational or "story driven" metaphor instead. The ultimate goal is to be able to tell your computer in human language what you want it to do and have the computer do it. e.g. "Ok Google, open the survey results Sarah emailed to me. Ok, now plot a histogram with markings at each standard deviation, oh and a pie chart too. Great, save that and email it to Kyle."

I'm not aware of what Microsoft or Apple might be working on, but Fuchsia is at least currently open source under BSD, MIT, and Apache 2.0 licenses.