Anthropic switched to HTML artifacts because they cut output costs by 8 cents...

https://research-wiki.win/index.php/Why_Did_the_HTML_vs_Markdown_Debate_Blow_Up_on_Hacker_News%3F

Anthropic switched to HTML artifacts because they cut output costs by 8 cents per document and handle 4.4 million views smoothly every month. HTML lets teams build richer, interactive planning docs, clearer code reviews, and flexible design systems