> AI is the primary audience for our writing, and the primary reason to reconsider our choice of markup format.

That's AI which must adapt, not humans. If AI can't adapt then it can't be considered intelligent.

> Some thawed-out-of-a-glacier journal editors still insist on two column formats, as if anyone still prints to paper.

Narrow text is easier to read because you don't have to travel kilometres with your eyes. I purposely shrink width of the browser when reading longer texts.