You are correct. However its not for the same things. S3 is high latency, HTTP semantics, no locking mechanism. EFS is low latency, high throughput shared fil

You are correct. However its not for the same things. S3 is high latency, HTTP semantics, no locking mechanism. EFS is low latency, high throughput shared file system with standard posix interface. everything can write to standard files. Not many things can write using S3 effectively.