And of course, he wrote it in plain ANSI C for the efficiency.
Given some arbitrary metric it's generally not the best to compare yourself with the best of the best (on that metric), just doing the best you can do and striving to learn and improve (and live and be there for your family etc.) is more then good enough.
Fabrice seems to know an insane amount about how computers work, knows all the CS stuff, has a tight grasp of all kinds of algorithms, great math intuition, and a lot of time on his hands to write OSS code. I bet he spent a lot of time learning the basics.
I would not at all feel bad about not measuring up anywhere close to Fabrice Bellard. Be happy with what you've done.
If necessary take time away from social media, including HN. Personally I've stopped visiting most social media and simultaneously feel more satisfied, less harried, and also have had more time to accomplish some small personal projects.
https://github.com/emscripten-core/emscripten/graphs/contrib...
and an article from 2012 about using it
https://www.webpronews.com/easily-port-c-to-html5javascript-...