How to write a cross-platform desktop application?

Question

User interface

After googling, I still couldn’t decide on what to write a cross-platform desktop application in 2019.
Tell me the language and gui libraries, frameworks for writing this miracle.
We need a progressive language with a gui library, with future prospects, a progressively growing or already large audience on sites such as stack overflow github, etc.
In terms of design, I need such a gui so that I can attach my own widgets that the designer will draw.
In terms of cross platforms: Windows linux Os
Learning a new language if it has a large audience is not a problem as long as there is only a little experience in python.
Here's everything I googled.
js Electron
go+ qt
python + qt\kivy Found
nothing else,
C++ , C#, java do not offer.

Answer 1

C++/Python and GUI on QML.

Answer 2

Java. No options, as it were)

Answer 3

Qt and gtk+ are screwed to many languages, but with all sorts of compromises.
What's wrong with C# and java and C++ I don't understand Qt.
Go is an interesting language, with its cockroaches, of course, you can blind gui, but so-so, it’s not for that.

Answer 4

Well, you threw out the most suitable)