Restic, it has native S3 compatibility and when you combine with something like B2 it makes amazing offsite storage so you can enjoy the tried and true 3-2-1 backup strategy.
Also fedora magazine did a few posts on setting it up with systemd that makes it SUPER EASY to get going if you need a guide.
I have an ansible role that configures it on everyone’s laptops so that they have local, NAS, and remote, B2, backup locations.
Works like a charm for the past 8+ years.
Why? And what would be a replacement for it?