Hard disagree. I can't even tell the difference the majority of the time, and I work with Qt every day (and love it)... probably most other people can't tell either. I never found it hard to build, and as far as other languages go, I have had great success using it from both Python and Swift rather easily. I don't think there are any better choices for a stable and mature framework with anywhere near the feature set.
Using a native toolkit built for Rust has massive productivity benefits when writing programs in Rust. Last I checked the GTK bindings for Rust were rough at best, I don't even know if they exist for QT.
The people using the DE don't care what programming language it's written in, so it's absurd to ask users to accept a rough/inferior/buggy/inaccessible system because an experimental UI library was more enjoyable for the developers.
