If I remember correctly this "standard" was setup by someone but without involvement of any of the major AI players.

This is just a redeux of the early web.

https://news.ycombinator.com/item?id=48411569

BTW why should Chrome even consider rendering a .txt file as markdown?

There is an enshittification cycle at work. The web used to be good, predominately text, and useful, 25 years ago. Then... slowly... we added javascript, then AJAX, CSS, flash, interstitials, popups, marketing, social media, algorithms, doomscrolling... gradually but surely turn it into the unusable cesspool that it is today.

Now we have AI! I think a big part of its utility is that it gets us back to text/information, and lets us bypass all the "beautiful" design / nonsense on the material it is trained on.

However, AI is just beginning its enshittification cycle - now that it has a critical mass of users, it is an irresistible target to start slowly adding ads, misinformation, conspiracy theories, and whatever else people can dream up, until it also becomes unusable and the cycle repeats.

Result: no such item.

From where do you got the idea that adding /llm.txt to urls will produce markdown?

I imagine Claude could zero-shot a Chrome plugin for that.