These apps predated LLMs "getting good".
Both have an enormous number of paying customers and you don't just disrupt that for a language change.
Anthropic literally rewrote the whole runtime CC is based on in another language. And even then they still not dared to migrate it away from React.
Anthropic literally rewrote the whole runtime CC is based on in another language. And even then they still not dared to migrate it away from React.