Free and Open Source Software

I've used borg for a while and like it a lot. I would say your best option for pure linux is borg+borgmatic/vorta just because borg is battle-tested.

If you run any other OSs and don't mind a relative newcomer, I've found kopia to be easy to recommend to my windows friends. At this point kopia has been around long enough (~4 years of actual beta) that I think it's safe to trust its integrity with personal data. It has all the important features from borg in a cross-platform solution, so it's also a viable alternative for borg on linux if you don't like borg's frontends for whatever reason.

I only have backups of my important files, encrypted and synced through rclone.

For my Ubuntu desktop, I use the builtin backup tool to take backups on my NAS. For my homelab, I have everything running on Proxmox and my Proxmox backup server takes care of the homelab backups.

I've used Borg for years now. It's been rock solid. I test my backups regularly and have done several actual recoveries. I trust it with my data, which is the best thing I can say about backup software.

I'm currently using TimeShift to backup my desktop onto an external hard drive (the why is because of how simple it is to use) and I'll be making a copy of anything I upload to my jellyfin server onto the external hard drive as well. I hope to eventually have a dedicated backup server and have a duplicate of it at a friend's house for offside backup too