IMO it's not ideal for Rust to have only Rust specific toolkits (at least they need to have other language bindings)
I've tried using Qt (non QML, using rust-qt) last week... initially things were looking fine (despite unsafe everywhere)... but I found quickly that I need unsupported things (deriving from C++ classes), and the project isn't really maintained anymore, so I'll need to so some low level work myself if I want to proceed.