Anthropic switched to HTML artifacts from Markdown to speed up internal work...

https://elliottkykp923.yousher.com/is-markdown-only-popular-because-of-the-old-8-192-token-limit-era

Anthropic switched to HTML artifacts from Markdown to speed up internal work like planning, code reviews, and reports. HTML cuts output costs to just $0.08 per file and loads content 5x faster, which boosts productivity