Hetzner + a HDD backup would basically get you to 3-2-1.
As a rule of thumb I’d keep the SSDs for live data and HDDs for backup.
Hetzner supports multiple good backup tools so you have options, and their prices are decent.
But please stick to Restic (or Borg) because they’re actually designed for backup and have built-in encryption, compression, deduplication, integrity, recovery etc. Don’t use “sync” tools like rsync.
Please, please, please assume that any of the SSDs and HDDs and cloud storage can dissapear at any time. Sit down and run some scenarios on paper, see what you’d do in each case.
Also a good idea is to sit down and categorize all your data on a scale of “how much my life would be over if I lost this”.
Sometimes super-essential data can be very small. For example a list of things to do in case of untimely demies (a “digital will”) can be a single text file that can be easily stored (encrypted) with family members. EncryptPad is a cross-platform text editor that uses open, standard encryption and can use a simple password.
If you need an extra form of backup media for ultra-essential data, Blu Ray optical discs are still an option. They are specifically designed for this and an USB optical writer is cheap.
Last but not least, store your “cold” backups in proper storage enclosures. For HDDs I like Orico padded boxes, for Blu Ray’s use a “CD wallet”.