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

https://stateofseo.com/can-live-artifacts-run-a-content-calendar-that-stays-updated/

Anthropic switched to HTML artifacts because they cut output costs by 8 cents per file and handle 4.4 million views with less lag. HTML lets their teams build clearer design docs, smoother code reviews, and richer reports compared to Markdown