This is what I think would be the best scenario for keeping backups and archives in one Org.
Firstly you must design your backup policy. It should include different types of backups, retention time, frequency, etc. These backups should be available to you in case if you need fast data recovery. You need fast storage to complete backups fast.
Secondly, you should design your archiving policy. This includes your long-term backup policy. Normally you should secure and keep these backups in some secure place, cloud, or some distant location. You don’t need SSD or NVMe. Normally you will need these backups in case of a real disaster.
What I think should be implemented in urbackup as an extension to its archiving feature is the ability to export backup sets to some external drive, or different backup location. These backup sets should be enough to restore the backup in case of disaster. This procedure should be manual, because normally it should be done by some it staf.
I read about and tested some fantastic features as COW images, but archiving(exporting) of such backup to external location and restoring path is not so natively.
Just wanted to share my thoughts.