Anthropic switched to HTML artifacts instead of Markdown because it speeds up...
https://www.slideserve.com/aaron_ward92/what-s-a-practical-html-artifact-layout-for-a-code-review-with-3-findings
Anthropic switched to HTML artifacts instead of Markdown because it speeds up their workflows and improves clarity. With HTML, they cut output errors down to just $0.08 per document and handle 4.4 million views monthly without breaking formatting