A lot of players entered this space and some are actually profitable companies, but are none are as popular as Electron. aside from Javascript and WebAPIs, Electron is also free as in free beer.

Qt: is truly cross-platform, supporting Mac, Windows, Android, iOS, and even LG TV webOS. VLC uses Qt and is rock solid on all platforms it runs. It is very expensive for commercial development.

Xamarin: run on all major operating systems, and mobile, they were profitable. C# is much better language that C++ or Javascript. They became free to use once Microsoft acquired them