> I find it difficult to read a markdown file of more than a hundred lines.

Apologies if I'm slightly demeaning here, but what? Markdown is largely plaintext. Unless the output is completely littered with markdown formatting (specifically, imo, tables and maybe links would be the hardest for a human to parse), is this not just saying "I have a difficult time reading large bodies of text" (which is of course fine - people prefer different ways ingesting information)

From reading the post, this seems like a "I personally prefer more visual, interactive elements in output" rather than "agents using markdown leads for less understandable output", and not at all what I would recommend for the average person to use unless said agent or interface or whatever had an extremely seamless way of displaying the HTML. If I had to open the agents response in a browser every time I wanted anything detailed I would lose my mind.

I've certainly had agents generate more rich visualizations such as through html, but I can't imagine using that as my default.