I use Duplicacy which backs up to Backblaze B2. I looked at Backblaze Personal Unlimited Backup ($7/mo) and from my understanding, the backups made with it are tied to the licensed computer. With B2 ($0.005/GB) it's just storage that can be accessed from anywhere (similar to AWS S3).

I've used Backblaze within their free tier with Kopia.io and its been working out well. The scheduled tasks, and retention policies you can set yourself too. The cost of a paid account on Backblaze is inexpensive as well.

I use and recommend rclone.

IDrive Is the cheapest and it's what I use. They allow Linux backups and it's 1/3 the price of backblaze buckets. They also give the same amount of backup storage in cloud storage. Encryption is done locally before uploading. I think I got 5TB for $70? That's all I need for critical data. All the rest of my 100 TB of data is Linux ISOs.

Backblaze B2 with Duplicacy here as well. Lately I've been looking at Azure and their archive tier storage as that's way cheaper, granted with the rather obvious caveat of twice as expensive to pull things back from, but for the actual archival of stuff that I hope I never have to pull back that's a bit moot.

Raspberry pi and an external drive at a relatives house. Cloud is too expensive for the amount of data I need backed up.

I currently don't really have any and it stresses me out. I have been considering going to something like Amazon glacier but I hate the idea of paying someone monthly,even if it's a dollar or something. But definitely have not ruled out a raspberry pi and a large USB hard drive at my parents house.