And React has that "web development" ecosystem taint... I'd definitely lean towards Flutter in this case. It's neat, tidy and a contained ecosystem. It may not be fully perfect, but for cross platform UI's I think it's the way to go.

My only question is - say if one uses Rust, is flutter_rust_bridge the way to go?

flutter_rust_bridge is what rustdesk uses with pretty good success, it's where I first discovered it.