The Slowpoke
Slow, repeated renders make global readers wait and hammer your origin. Cloudflare caches the response at the edge, so the first visitor pays the cost once and everyone after gets it instantly.
Try it
Load the page.
First load is a cache MISS (a ~700ms origin render). Load it again and it's a HIT from the edge cache, in single-digit milliseconds. Purge to feel the slow path again.
Workers Cache API. The rendered at timestamp stays the same on every HIT — proof you're getting the one cached copy, not a re-render.