I'm cheap so I have multiple small SSDs rather than a single 8TB+ one. The OS lives on an NVMe SSD which has not much else on it. Largely because my "home" directory is actually a toilet where every misbehaving application dumps piles of "special stuff", so 500GB of SSD gets filled up fairly regularly.
I have a 2TB disk of mostly music, which is mostly FLAC. Music is in classical/vocal/pop folders then artist/album subfolders except that classical is mostly composer/album. A scary amount of that is stuff I have ripped+scanned myself, because even the modern artists so often give me the choice between stupid plastic trinkets or compressed garbage. Buying 320kbits mp3 and discovering that it sounds upsampled from 128kbits is a mistake you only want to make once.
I have a 2TB "work" disk with virtual machine images, code repos, whatever it is that piles up when I work. And that disk is a bit full. It's mostly organised by employer/project, then yyyy-mm within project folders if necessary.
I have a 2TB disk called "stuff" with photos, documents, ebooks, calibre library (yes, I store them twice. Ebooks are small and Calibre has lost the plot before), software installers I've paid for or that I think might vanish, personal websites, all that stuff. Most are in relevant folders then for docs and photos there are dated subfolders. Sometimes those are in year folders because at times I've take an awful lot of photos (photos/2009 has ~800 subfolders). There is also docs/tax/{year} for obvious reasons, which have everything from photos of receipts to hours-worked spreadsheets.
It's all backed up onto legacy disks with one copy in the office I used to work in (still my employer, but covid) and one in the shed. A couple of those disks have working files and original RAW files for the photos as well, but that's a 6TB disk by itself.