Calling other languages like "none of the tooling" in the "why" section sounds like a huge self-roasting since CCL does not have, say, highlighting/LSP/FFI for adoption.
Glad to see Google employee still has 20% of their time to do side projects!
Python UI is especially interesting for ML/LLM folks who can build demos without changing tech stack.
I appreciate OP's ideas about how this project is compared to Streamlit?
However, there is no case for more complicated, multi-file changes or architecture stuff.