AWS's [docs on EFS performance](https://docs.aws.amazon.com/efs/latest/ug/performance-tips.h...) say:

> Don't use the following mount options:

> - fsc – This option enables local file caching, but does not change NFS cache coherency, and does not reduce latencies.

If the S3 Files sync logic ran client-side, we could almost entirely avoid file access latency for cached files and paying for new expensive EFS disks. I already pay for a lot of NVMe disks, let me just use those!