It's something I wonder about as well. We're building real-time performance critical software, so we don't have much of an alternative. Given these constraints, we also ruled out Electron, Avalonia, React Native early on.
We're using Qt Quick which doesn't get nearly the love it should. I was a web developer for 5 years in a past life, and I'm pretty blown away by how pleasant and well-designed Qt Quick's QML language is. One of our team members created Canonic, https://www.canonic.com to explore how the web might look if QML was used as the document markup for the web.
The popular opinion around Qt Quick is that it is best suited for mobile or embedded projects with a dynamic UI, animations, etc. But over the last few years, it has really become a great desktop solution – to the point where Qt put Widgets into maintenance mode and is focusing efforts on Qt Quick across desktop, mobile and embedded targets.
With Qt 6, the GUI is drawn using native graphics acceleration: Metal on macOS, DirectX11 on Windows, Vulkan on Linux. This makes it really easy to bring in a texture you're drawing in some other piece of code outside of Qt. As a result, the QtMultimedia framework in Qt6 is zero-copy on most platforms with the FFmpeg backend. Frames get decoded if a GPU HW decoder is available, then this texture can be read directly by QtQuick and then rendered by the display server without ever being copied. I don't think there's a single other cross platform framework out there that achieves the same level of usability, performance and easy access to platform native APIs.
Here are just a few non-trivial desktop apps that come to mind using Qt Quick:
- Denon Engine DJ - https://enginedj.com/
- Mixxx - https://mixxx.org/
- Spark AR Studio - https://sparkar.facebook.com/ar-studio/
- Gyroflow (written in Rust, with QML frontend) - https://github.com/gyroflow/gyroflow
- MuseScore 4 - https://musescore.org
I definitely see Qt and Qt Quick technologies as a competitive advantage for us. We can develop the frontend quickly with QML / Javascript. We get full graphics accelerated GUI performance. Our app running under an average use-case idles at 100MB of RAM, which is basically equivalent to what a running instance of Finder on macOS uses. A full 1/5 of what Discord, Slack, Steam, etc use.
If you want to build real-time, high performance, native desktop apps, we're hiring. Email in profile.