It'd make sense to rename WebDev Arena to React/Tailwind Arena. Its system prompt requires [1] those technologies and the entire tool breaks when requesting vanilla JS or other frameworks. The second-order implications of models competing on this narrow definition of webdev are rather troublesome.
[1] https://blog.lmarena.ai/blog/2025/webdev-arena/#:~:text=PROM...
To me it seems so strange that few good language designers and ml folks didn't group together to work on this.
It's clear that there is a space for some LLM meta language that could be designed to compile to bytecode, binary, JS, etc.
It also doesn't need to be textual like we code, but some form of AST llama can manipulate with ease.
Plenty of training data to go on, I'd imagine.