Definitely a cool idea. I've thought a lot about this idea as I'm sure many others on this post have. A protocol for just HTML/CSS (and a lightweight bridge) could be cool to see. This desire was why I was initially on board with AMP (before I saw the bigger problems with that format.)

I've also thought about a JSON-only protocol. In my mind this would make it simple to do AJAX-type interactions for loading content (the core benefit of JS to me) while still excising JS in its entirety, but I haven't thought it through very far admittedly.

This is the first time I'm hearing about Gemini and I'm really intrigued, especially how it's handling input and identity. There's potential here...