I'd say the "bytes" being transferred are very different. Netflix has a (relatively) small number of large content pieces, and a CDN node would hold the hottes

I'd say the "bytes" being transferred are very different. Netflix has a (relatively) small number of large content pieces, and a CDN node would hold the hottest items. IA has 430 billion individual pieces of data, on average much smaller than a piece of Netflix content. So each "byte" transferred from IA is "more work" to produce, and less likely to come from some kind of cache.