Notwithstanding something exceptionally rare, why the need to back up FLACs on S3?

I back up my music collection locally, and I have double-redundancy of sorts (it's backed up to a RAID 5 array on a file server, so in theory it could withstand the failure of the original drive and one of the back up drives), but if worst comes to worst I could just acquire everything again.

With a couple of exceptions they're just lossless copies of widely available music recordings...