Author here and it is true that costs within a region are free and if you do design your system appropriately you can take advantage of it but I've seen accidental cases where someone will try to access in another region and it's nice to not even have to worry about it. Even that can be handled with better tooling/processes but the bigger point is if you want to have your data be available across clouds to take advantage of the different capabilities. I used AI as an example but imagine you have all your data in S3 but want to use Azure due to the OpenAI partnership. It's that use case that's enabled by R2.