You need SGs because not everything in the world lives inside a K8S cluster or flows through a CNI. And you need IAM because if you have 10 users and 10 resourc

You need SGs because not everything in the world lives inside a K8S cluster or flows through a CNI. And you need IAM because if you have 10 users and 10 resources but not every user is allowed to perform all actions on all resources you need policies. Policies apply (generally) on roles, actions and resources. IAM that only works on some random resources but not on others are pointless, unless you have a very small setup (i.e. less than 100 resources, less than a small office of users), but at such a small scale, you shouldn't even be thinking about AWS (unless you are on track to scale 1000x). S3 isn't just "I have many files and it needs a lot of disk space". Like I wrote, if you just use base S3 API primitives then no, you're not really using anything AWS-specific, and making a comparison between something that does more than you need seems odd to me. Edge storage, cold storage, cheaper storage based on reductions of redundancy or access times, mirroring, versioning, multi-level IAM (integrated with the rest of your IAM) are all things that make the difference between "look at my virtual USB disk" (most MinIO configurations out there, the unsupported ones that is) and "durable and reliable multi-level object storage, configured for my needs".