

Tape storage is the gold standard but it’s just not realistically applicable to low scale operations or personal data storage usage. Proper long term storage HDDs do exist and are perfectly adequate to the job as i specified above and i can attest this from personal experience.
Here’s a copy paste from superuser that will hopefully show you that what you said is incorrect in a way i find expresses my thoughts exactly
https://superuser.com/questions/284427/how-much-time-until-an-unused-hard-drive-loses-its-data