What do you mean if? The internet is built on html. Markdown is a random flare up of an annoying annotation standard pushed by LLMs. No one used Markdown anywhere near at the scale of html before ChatGPT
HTML is a communication layer. Hardly anyone is writing it directly. Using React etc. or whatever or even LLM.
My point is: what’s the total number of html files in existence? Billions. What’s the total number of markdown readme files.