Have you looked at Arq[1]? It deduplicates, encrypts, compresses, backs up to most major cloud providers and SFTP and Minio, is available for macOS and Windows. We've been improving it for 10 years. The data format is open and documented[2].
You've probably heard this before but there are a lot of people who'd be interested in a cross-platform (NAS/Linux/BSD/Raspberry Pi) version with a command-line or web interface.
As is it's really best for workstations rather than the NAS/servers a lot of people who care about their data use (not just basement-dwelling data hoarders but also professionals like photographers and videographers).
I currently use Borg on my servers, and Arq on my client machines.
I'm quite sure if Arq was available in a command-line version for Linux/FreeBSD, i would use that instead. It has been nothing but rock solid on my client machines.
Restore through the UI is a bit wonky, but once it's started it works well.
My biggest reason is probably that i prefer to use the same (well known / proven) tools across the line.
I don't think Arq brings something to the table that Borg/Restic/Duplicity doesn't already provide, besides a piece of software i'm familiar with, and trust. (and trust doesn't come easy when it comes to backup software!)
As i wrote, i already use Arq on my client machines instead of the mess that is "TimeMachine over wifi", but when it came to backing up my NAS and server/VPS, i had to look for something else, as Arq is not available on those platforms.
My use case would be backing up with Arq from a FreeBSD/Linux NAS/Server to a remote (networked at least) target, and in case of a full restore, i would use the command line as well.
I would then use Arq for Mac/Windows for "plucking" single file restores.
(Note: I work on Arq)
[1] https://www.arqbackup.com [2] https://www.arqbackup.com/arq_data_format.txt