Wish I could upvote this comment account more. Too many people look for something new and shiny when trusty ol tools are sitting right there. :)

Inflated egress costs might make this prohibitively expensive, $80 per TB at GCP and AWS

Well having backups help, but I certainly can’t migrate my infra to rsync.net on moments’ notice (or ever since rsync.net does storage and nothing else) so my customers aren’t affected.

I don't think that technology exists. Sorry.