Non-uniform non-platform-widget based rendering of applications is not something I would call state-of-the-art. The overton window has only shifted to that recently. I would claim that a small statically linked executable displaying a native window containing native widgets is state-of-the-art, and would blow everything ever created in webland out of the water instantly in terms of resource usage and performance.

Since you named it explicitly - why would my application want a web inspector or CSS layouting overhead if the goal is to display a small batch of controls? This is exactly the mindset I meant when I wrote my post.