I'm amazed that it has been 15 minutes and noone have said Rust yet ;)
It you want to explore the Rust option, here is an overview of the status of GUI toolkits in Rust: https://areweguiyet.com/
I think wxWidgets has binding for other languages like Python?
Last time I had to do a gui, I chose JavaFX, and it was fine. But I’m still looking for native options, even if I have to implement the ui 3 times.
Edit: to clarify, I’m looking for something beyond C/C++