Comment by cyber_kinetist

There is Slint (https://slint.dev/), which was a company founded by ex-Qt devs and seem to be trying to make a better alternative to Qt. The core engine is built wiht Rust, but they also provide C++ and JS bindings and also have a QML-like scripting language you can use to design UI quickly. So far I think they've solidified their revenue model by catering to embedded devices, but I haven't seen a solid usecase for desktop apps (yet...)