If you are gonna go for TrueNAS, try Storj with TrueNAS Cloud task. TrueNAS made a partnership with Storj and the price is very good. https://www.truenas.com/truecloud-backup/

TlDr; The data is encrypted with restic and sent to Storj S3 storage that is further fragmenting it (and encrypting it too - so double encryption) into multiple pieces (with redundancy) and storing on other peoples TrueNASes (you can also provide your unused space btw and gain some small money back).

I am in process of setting this up (already run a working test backup) and I didn’t find anything that’s better than this integrated solution. Very cool!

I am in the same situation, looking how to use my 1st pi. I am already using AdGuard, Nginx and home assistant on my pi4, so I am looking for something more niche but very cool 😀

I did just that. I also put ssd to a flopy disk bay and I screwed one drive on the outside of the case 😀 works like a charm.