This is coming from personal experience/opinion, but after trying to create a simple app in GTK4 Rust bindings I was so confused because of how alien the programming style was compared to typical Rust programming. After trying Iced it was much simpler and made so much more sense, no silly decorators or anything, you can define the view and the update loop separately, and interactions are handled by messages using pattern matching. The inheritance based OOP doesn't work well with Rust, and Iced has none of it, because it was made for Rust specifically.

I'm guessing QT bindings are similarly in a different style of programming and can't imagine that meshing well with native Rust code. Iced has a lot of merits to it and having the opportunity to both help it develop and use a native Rust framework in a Rust project makes a lot of sense.