I prefer to get bleeding edge LLMs to use old, time-hardened technologies. They are more stable, I trust they're not going to change out from under me, and it is more transferable. The ergonomics of the actual markup don't matter to me, since I'm not writing it, so I'd rather the more powerful, more training data option.
Just one example: Every university and academic publication in the world give LaTeX formatting templates, examples courses etc.