It seems hard to find a universal recommendation. I've heard good things about Arq although it didn't work well for me personally whereas ironically Duplicati did, although I'm currently using Restic.
I've had a good experience with Kopia [0] for over a year. Linux and Windows boxes all writing to the same repository, which is synchronized to both B2 and a portable drive every night. The one thing it lacks that I'd like is error correction, so I store it on a RAID1 btrfs system. ECC is apparently being developed [1], but is currently experimental and I believe requires a new repository.
I've had issues trying to use multiple different Kopia repos from one machine. (A dedicated back-up server basically)
With compression landing in the most recent Reseic release, I'll probably switch back to that for my servers. Though I'm still keeping Kopia for my clients where I like a GUI once in a while.
After hearing a lot of praise for Arq here, I tried it out hoping it would become my new Windows backup solution. (I'm looking for a linux one too, but Arq doesn't do linux). But I was very underwhelmed. The user experience for browsing file versions in time was not really there. If I recall correctly, I could only browse by snapshot. And it was extremely slow for just a few gigabytes. The backup process didn't inspire confidence, I was never sure if something had interrupted it or what the status was.
I recommend Arq also at least for Windows (have not tried on Mac). I'm using Arq 7 cloud (something like $60 a year) on a Windows desktop. The software is straightforward, generally stays out of your way, gives alerts when needed, reliable, saves versions similar to time machine, fairly configurable, and backups are end to end encrypted, and can be saved to Arq's own cloud service, any local media, and most other cloud services. I had lots of permission errors when starting for a small bunch of files but was able to fix them out by either resetting permissions or excluding files (e.g., caches). I think these are the kind of problems you can expect on Windows when using Shadow copy, no reflection on Arq.
Instead, I'd recommend Arq backup.