I believe it's never been a better time for cross-platform desktop GUI. Vulkan API works on Windows, Android, Linux. Even web has Vulkan support. The only outlier is Apple.

On Linux, Wayland provides better drawing surface and input API.

The only missing piece is a high-level GUI and Vulkan/Metal compatibility layer. Along with ancient issue of packaging of course.

Didn't they also invent Electron for their Atom editor when working at GitHub? Which then was hijacked by Microsoft and VS Code. Was Electron (Atom Shell) a core differentiator of Atom? Absolutely. Was it a business decision? No, it was a dream to use javascript/html/css to build a desktop editor. I think, similarly, Zed was an experiment to build a modern desktop app without any C++ legacy or OS API wrappers.

Those creators own their company in the case of Zed, so it is a business decision. Otherwise they could've just gone with Electron again. The business decision is that they wanted to be different in the market, the speed of vim with the IDE capability of VSCode.