I had backblaze, and it’s really a bummer they don’t support linux. The closest one I’ve found is Icedrive, but it costs a bit more. I don’t mind paying a bit more though for a FOSS solution (technially not free but yeah). I probably only have 2 TB of actual important stuff but it would be nice to have more for future.
I’ve just installed kopia on my home server. The web interface is super simple and it has exactly all the features I want (encryption, differential & retention tweaking).
It works with S3, so I pay less than a cent per GB for a cloud provider from my country. This pricing works best for me because I only backup about 20GB of data.