It's successful because it's been kept away from the kind of programmers who think the time spent to endlessly specify everything four times is nothing compared to the sadness of losing a byte or a cycle. These are the descendants of people who hundreds of years ago would have insisted that real work is in Latin. C++26 is available for them, or Node/React with hundreds of dependencies if they want JavaScript, or they can even compile and run whole operating systems into WASM now, or anything else. Just let JavaScript be the domain of people who do other things for fun.