I can sort of confirm this. Disclaimer: I work with C++ and Qt and only know some basic HTML and JS. I have worked on a project where we reimplemented an HTML5

I can sort of confirm this. Disclaimer: I work with C++ and Qt and only know some basic HTML and JS. I have worked on a project where we reimplemented an HTML5... application (information omitted to protect possible secrets). We did it in a quarter of the time with IIRC a tenth of the staff from the original, according to those who did the HTML5 version. Line count was also lower. Of course not having to redo high-level design and some lower level services was a massive benefit for us, and HTML5 frameworks weren't as good at the time. Perhaps the most important point is that while they got a skeleton up in reasonable time, things slowed down greatly from there. The HTML5 / JS code was kind of hard to understand due to callback hell, and getting smooth performance took a huge amount of work. In the Qt version, we implemented it following some best practices and performance was great right away.