We are digital librarians. Among us are represented the various reasons to keep data -- legal requirements, competitive requirements, uncertainty of permanence of cloud services, distaste for transmitting your data externally (e.g. government or corporate espionage), cultural and familial archivists, internet collapse preppers, and people who do it themselves so they're sure it's done right. Everyone has their reasons for curating the data they have decided to keep (either forever or For A Damn Long Time (tm) ). Along the way we have sought out like-minded individuals to exchange strategies, war stories, and cautionary tales of failures.
HDD cache hardly matters these days. Latency sensitive stuff should be stored on SSDs or cached within system RAM. It is only relevant in edge cases.
If anything more cache can be a bad indicator as HDDs with a lot of it tend to be SMR drives. However, all Ironwolf (Pro) drives should be CMR.