Judging from the hints in this article, I'm going to guess that the proposed solution will be Canvas or SVG based layout. Every time I do Canvas or SVG layout, I remember just how good HTML is at handling edge cases, particularly around resizing and accessibility.

The separation between semantics and presentation is what allows the UI to scale from phone to TV console to desktop. It's why Android and Apple are both switching to a semantic (declarative) syntax. As Apple's WWDC keynote put it, declarative syntax lets you write one set of code that works and looks great on Watch, iPhone, and macOS.

Android uses Tk-inspired XML layout, although newer projects use React-inspired Jetpack on top. Layout is not easier, not more accessible, far more verbose, and at least as bug-prone as HTML/CSS.

Apple iOS uses a layout model that traces its roots all the way to NeXT in the late 1980s. At every step of the way, they've dithered between flexible layout (like HTML or Tk) and pixel-precise layout. Newer projects use React-inspired SwiftUI on top of classic MVC views. When you hit an edge case with, say, navigating a complex UIScrollView, an experienced developer can spend weeks debugging it.

HTML/CSS has some pretty serious warts, but it's reliable, well documented, and provides accessibility out of the box. It scales from being an archival format to providing fancy UI experiences. However, the more you stray from vanilla HTML/CSS, the buggier the experience tends to get.

If you don't like HTML/CSS, the answer is not porting Android or X11 to the web, nor is it reinventing Flash or reinventing HTML in SVG. Just use Markdown text with React, Vue, Svelte, or any of a zillion other libraries.