The multi-region thing should be pretty apparent. It’s part of the core S3 design to provide distributed storage. Multi-region is distributing it over a larger area. If you want to implement multi-region storage yourself, you can do it on S3 and pay a high cost for duplicated data, or you can try to implement your own S3 alternative.

For CAS, one example is backup jobs. You can run backup jobs to S3, but there are some safety issues if you want deduplication and you want to expire old data.

> if S3 is too simple

CAS isn’t some kind of super complicated, technical thing.

It would be nice if S3 had this small, incremental additional feature. That’s all. It would mean that some people don’t need to fire up DynamoDB just to do something you can already do in, say, GCS.