> Please correct me if I am mistaken; also R2 is not a CDN, and more like s3 in terms of delivering from the edge
Yes, it uses Cloudflare's edge network and caching infrastructure when you use a custom domain (really the only option because usage of the default domain is very limited). So yes, it's a CDN :-)
https://community.cloudflare.com/t/cdn-support-for-r2/514573
> currently using s3+cloudfront for mp4 storage+delivery, and would like to move to something better if possible.
What I have found is that (A) the egress costs are extreme compared to R2 (remember, R2 does charge per read/write though) but (B) storage is cheaper on S3. You should do a study on your storage and egress, but unless you are storing way more than your egress TB, it's probably a good deal.
Cloudflare also has a mechanism for transparently pulling content from an upstream S3 compatible store into R2. I think it's called Super Slurper iirc