Depends on the details. For example, AWS Glacier may be cheaper than S3, depending on the frequency the images get accessed (it probably won’t be best for you, but there’s a possibility that a mix of S3 and Glacier fits your use case better than putting everything in S3)
Glacier certainly will be slower, though.
You also may have requirements w.r.t. access time, may want a search facility, may want the ability to serve multiple image sizes, may have legal requirements such as the GDPR, copyrights that differ across the world, etc.
