We can write vast numbers and volume of objects to S3 per second using concurrent processes (spawn 1000 lambda invocations and try it). As long as I have the network bandwidth, I can push stuff essentially as fast as I want. Is that true for EFS? Handle limits. Network interface limits. Protocol limits.

I’m not saying that S3 is perfect or even good for most workloads. However, it is most excellent when the workload fits.

fast is an overloaded word. Could mean throughput, or latency. S3 throughput is incredible.

note, I worked on Amazon at S3 2015-2017.