>> Thanks to V8 you can definitely achieve good enough performance with JavaScript for most applications
The point I argued above isn’t that JS is slow. It’s that JS will probably always be slower than well written C code. I still write far more JS than C, because my time is usually more valuable than the computer’s.
That said, games are far from the only place where every ms counts. Performance matters in database servers, operating systems, real-time applications (eg robotics), text editor typing latency, UI responsiveness, 3d modelling software, video encoding, cryptocurrency mining, browser DOM rendering and so on.
I love JS, but native code is not a special case. Despite the best efforts of Electron, I suspect most of the globe’s aggregate clock cycles are spent running code written in languages other than JavaScript.
Ironically it is now used as the language to beat.
Games are a special case where each ms counts. Globally, the number of LOC written for consumer or business software dwarfs that of game code and for these kinds of applications JS is well within the realm of performant enough. That assumes you're not doing your presentation layer using the DOM though which is still garbage wrt performance. Luckily there are things like Qt to make high performance UIs in though.