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...
Funnily, training of these models feels getting cut mid of v3/v4 Tailwind release, and Gemini always try to correct my mistakes (… use v3 instead of v4)