No, my first job was as an intern at IBM and my first non-intern computer job was in an AS/400 shop, and my last 2 years I've been an 'AWS Architect' and it's the same thing exactly - the guy with a good memory knows the entire IBM product line now knows all the obscure and bizarre AWS products. It's not just product certifications but even you end up building around arbitrary limits in the big company implementation rather than just modifying the open source code or adding glue layers to get what you want.
I have had to write weird proxies just because of some missing AWS features, and it made sense because, unlike the last twenty years of my computing career, I don't have the source code to all of the code running in the environment.
But yeah, if I were recommending options to a web group, I'd 100% tell them to use R2 and populate it object by object from S3. Although I suppose all the "it's ok to put this data into S3 with these controls" agreements will need to be redone for the new use case.
I have had to write weird proxies just because of some missing AWS features, and it made sense because, unlike the last twenty years of my computing career, I don't have the source code to all of the code running in the environment.