Backblaze B2 customers will be able to download data stored in B2 to Cloudflare for zero transfer fees. This happens automatically once Cloudflare is configured to distribute your B2 files.
I really don't care about the cost of storage. In my case it's the bandwidth costs that were killing me.
If it was available at the time, I would use R2 if only for simplicity.
If I was using Cloudflare Workers it would be another reason to use R2: I assume that it's easier to use and faster to use than any other storage system, since it's on the same network and written by the same people.
Also, exposing Backblaze via Cloudflare has it's issues. I ran into Cloudflare caching 404 responses from Backblaze and Backblaze being slow to make write visible.
So I would write into Backblaze and tried to access that key via Cloudflare proxy. While the write was acknowledged to my client it wasn't yet visible via http endpoint so Cloudflare would cache 404 response. I would have to clear the cache to fix and then I've added 5 min delay "just in case" to work around this.
Yes, like it was yesterday (or today). It was a strange time where the term was often used for things that had nothing to do with the original meaning of the term.