Oh! Nice to hear from you again. Sorry I'm no longer on the ball these days, I have a wife and a son to look after now and the 'Web has completely gone off the rails from the web I was trying to build :/
I have spoken of Gemini before (https://mstdn.social/@kroc/110952073856751159) and that it's not a solution for existing web content. I think it's neat, but fundamentally flawed as a document format.
Choosing Markdown is about reusing what already exists to minimise adoption cost; I don't even like Markdown and think there's way better formats, but I have to acknowledge that a ton of web content is already written in Markdown before being converted and sites could begin serving the original files with minimal effort. It's up to browsers to innovate here.