More like: your company (or government agency) is critical infrastructure or of a certain size, so there are obligations on how you maintain your records. It’s not like the US or other countries don’t have similar requirements.
(Without knowing the precise nature of these laws) I would expect that they don't forbid you to store backups elsewhere. It's just that they mandate that certain types of data be backed up in sufficiently secure and independent locations. If you want to have an additional backup (or backups of data not covered by the law) in a more convenient location, you still can.
This kind of provision requires enforcement and verification. Thus, a tech spec for the backup procedure. Knowing Germany good enough, I'd say that these tech spec would be detrimental for the actual safety of the backup.
When you live in Germany and are asked to send a FAX (and not a mail, please). Or a digital birth certificate is not accepted until you come with lawyers, or banks not willing to operate with Apple pay, just to name few..