https://upload.wikimedia.org/wikipedia/commons/e/e8/Qt_Creat...
I always see Qt mentioned, so I'm definitely not trying to discredit it. I just never seem to see common examples with it compared to something written in Electron.
The comparison to Electron is somewhat flawed though. I mean, the GUI in an Electron application owes much more to whatever library they choose than to the fact that it runs inside Electron. Electron provides no particular GUI elements to the developer.
Now, don't let the screenshots color your impressions as to what kinds of UI designs are possible under Qt: Ripcord's UI is bare-bones on purpose; it's a selling feature. I bring up this application because it lets you do a more apples-to-apples comparison: IM clients these days are a poster child of an Electron app that uses orders of magnitude more resources than they should for the functionality provided. Ripcord lets you compare the experience and performance with a native app, implementing the same features but without overhead and gratuitous UI shine.
(And personally, I do use it for Slack/Discord instead of official clients.)
Autodesk Fusion 360 uses Qt[1]. (It's 3D CAD modeling software like Solidworks/Inventor). Some screenshots of its UI : https://www.google.com/search?q=%22autodesk+fusion+360%22+ui...
CAD/CAM modeling software is resource intensive and users always complain about slow performance when manipulating big files so writing that type of app in Electron/Chrome/Javascript browser engine would be worse than native C++/Qt.
That said, another competitor Onshape is browser-based and yes, people do complain about its performance.
Some other well-known desktops using Qt are Autodesk Maya and Wolfram Mathematica.[2]
[1] https://forums.autodesk.com/t5/fusion-360-api-and-scripts/wh...
[2] https://en.wikipedia.org/wiki/Category:Software_that_uses_Qt