Interestingly, this page has been edited to add a warning: "A snapshot is a frozen version of your volume that allows you to restore it to a previous state. It should not be regarded as a backup of your volume. If your volume is deleted, all related snapshots will be deleted too."
Here the right one which state that they are backup: https://docs.gandi.net/en/cloud/volume_management/volume_sna...
Here's the one that you quote (which isn't the same service): https://docs.gandi.net/en/simple_hosting/common_operations/s...
Be careful next time judging with that little knowledge of the issue.