But the text file has some markup syntax beyond human language? Point being LLMs are subpar for acting on formal grammars, like cracking a nut with a sledgehammer. That's why its important tools like 11ty and pandoc remain.

That’s somewhat true (in my case it’s it’s laughably simple though).

I also never said that tools like pandoc are obsolete now. Just in my case they are already overpowered and I might migrate to something simpler soon. Otoh i might just run the current version of 11ty indefinitely and never upgrade.