Have you seen Fabrice Bellard's QuickJS Javascript Engine?

https://bellard.org/quickjs/

This guy is my programming hero, this is a almost fully complete ES2020 engine in standard C98, and compiles to less than 300kbs.

Check this out even, he's using his other tools to run an x86 virtual machine in javascript, runs linux on it, and then runs his javascript engine on top of that. A true javascript sandbox within the browser. https://bellard.org/jslinux/vm.html?url=alpine-x86.cfg

fully complete ES2020 engine in standard C98, and compiles to less than 300kbs.

Let me guess: it is the slowest ever JS implementation with a ton of new exploits and no error reporting?