I work in a niche inside a niche. I deal with terabytes of storage, massive servers, a variety of storage tech, and I’ve been in interested in computers in general for… Around 40 years. (Yeah, I’m old.)
I have my own single person company and have worked in 40+ US states, done assignments in the UK, Norway.
AMA.
Honestly? It’s people not understanding that there’s no such thing as a perfectly reliable storage medium, and that it’s the PROCESS that keeps data safe.
Instead of saying “My RAID array has TWO hot spares”, people should be saying “I have THREE copies on TWO different media, in TWO locations, and I tested my offsite backups within the last 30 days.”
In my world, due to the size of the archives, it’s all proprietary software… So, consider learning large enterprise IT systems/software… Operating Systems, Storage Management, Tape Library management software, database engines, etc. I realize this is all moving to the cloud now, so regardless of which software/service stack you use, understand how all the pieces fit together, and become proficient at each of them, so you can be useful regardless of where the problem is. :)