Earlier quoted context omitted.
I think it's becoming reasonable to think consumer storage could be a limited number of soldered NVMe and NVMe-over-M.2 slots, complemented by contemporary USB for more expansion. That USB expansion might be some kind of JBOD chassis, whether that is a pile of SATA or additional M.2 drives. The main problem is having proper translation of device management features, e.g. SMART diagnostics or similar getting back to t…
As @wtallis already said, a lot of external USB stuff is just unreliable. Right now I am overlooking my display and seeing 4 different USB-A hubs and 3 different enclosures that I am not sure what to do with (likely can't even sell them, they'd go for like 10-20 EUR and deliveries go for 5 EUR so why bother; I'll likely just dump them at one point). _All_ of them were marketed as 24/7, not needing cooling etc. _All_…
Once you get to uATX and larger, this could potentially be via a PCIe adapter card too, right? For an SSD scenario, I think some multiplexer card full of NVMe M.2 slots makes more sense than trying to stick to an HDD array physical form factor. I think this would effectively be a PCIe switch?
I've used LSI MegaRAID cards in the past to add a bunch of ports to a PC. I combined this with a 5-in-3 disk subsystem in a desktop PC. This is where the old 3x 5.25" drive bay space could be occupied by one subsystem with 5x 3.5" HDD hot-swap trays. I even found out how to re-flash such a card to convert it from RAID to a basic SATA/SAS expander for JBOD service, since I wanted to use OS-based software RAID concepts instead.