Markdown is not context-free and therefore hard to parse.

Caching can be abused for tracking.

That's why both are solutions to the problems the Gemini project is trying to solve.

Why not? Why is it necessary to use existing approaches, even if they add a lot of incidental complexity? What does it hurt you that Gemini has their own custom markup language that's different than Markdown? You can set up your own little Markdown HTTP server, they're not stopping you.

Markdown has loads of bad design decisions for writing a parser... or being the (human) parser.

I've made an attempt to do better, it may be illuminating: https://github.com/civboot/cxt