Now that WinUI has a Rust API, I think using Rust is a no-brainer.

The app will be running on probably about a billion of devices, and Rust will reduce the footprint on each of those - assuming not a vibe coded clone app.

The additional effort isn't that big, and it would make the experience of maaaany users a bit better still.

Now extrapolate on all windows included apps and ui elements.

How much would that cost per license?

Maybe they fired all their experienced developers and only have cheap vibecoders now, I don’t know. The decisions of beancounters and lawyers that control these companies are mysterious to me.