> This would be sooo much worse from a UI point of view. All nice OS features (good text rendering, uniform text editing interface, accessibility, transparency) would all get chucked out the window.

This is what is already happening with people using sandboxed-runtime containers (like Flatpak) and webapp wrappers (like Electron). Desktop UX is becoming a hodgepodge of siloed runtimes and inconsistent interface paradigms.

I don't think Godot would be a great alternative to developing a conventional desktop app, relying on the OS-provided runtime environment, but if you're already deviating away from that, it might still be much better than Flatpak or Electron.

> Electron can definitely have great performance when the developers care about performance (VSCode).

But most Electron applications do not have great performance because they're not being developed this way. Using Godot would provide an easy-to-learn frontend environment (with a scripting language that might even be simpler than using web-derived JS) while still providing the performance of a game engine under the hood. So non-Microsoft developers who would otherwise use Electron might still stand a chance of releasing decent software.