USB cables are some of the worst designed crap I have ever seen in the history of computing. When you plug the cable in, it doesn't make a firm, snug fit, and jiggles around in place. If you press down on it it can even torque the connector right off the PCB.
I often have to design 3D printed housing to go around the USB plug housing to hold and lock the plug snugly in place, because the designers of both the USB ports and plugs are incompetent at designing something industrial grade that locks down firmly.
SCSI cables were fine, their ports were secured to the housing and they had nice screw locks so the cables wouldn't go anywhere. Any cantilever forces were absorbed by metal casing, not PCB. Super reliable.
I don't want to defend USB too heavily (as you say, it is certainly not "industrial grade," but I don't know what the equivalent of something simple and very strong like a Hubbell twist-lock connector would be in data transfer terms, and that's something to contemplate) but this really shouldn't happen with any halfway decent cables or hardware. It doesn't apply to the Raspberry Pi 4 in my experience, or any of my laptops or PCs. Phones and micro-USB are, of course, a special case and uniquely horrible.
> SCSI cables were fine
Except when they weren't, and then you'd have to spend fifty bucks (whatever that equals in 2020 dollars) to test and see if the cable was what was failing you, or the termination, or the jumper settings...
> but this really shouldn't happen with any halfway decent cables or hardware
Well, the best brand cables jiggle around. I'm talking Pi's, Macbooks, Pixel phones, you name it, they all jiggle around.
I've had RealSense cameras, StarTech USB hubs fail because of cable jiggling around in the port, and had to make 3D printed add-ons to grip the housing and prevent cable jiggling.
I've personally had WAY more problems with USB that SCSI cables, honestly. Also I break an average of about 1 USB cable a week; SCSI, DB25, DB9, DB15, BNC, and those cables never break.
BNC has always been trouble-free for you? That's interesting.
I think the only cable type that was entirely trouble-free for me over the years was the parallel printer cable with the truly awful Centronics connector. I don't remember ever throwing one of those away. Of course, that's not a cable that you'd plug and unplug much, which certainly helps.
I often have to design 3D printed housing to go around the USB plug housing to hold and lock the plug snugly in place, because the designers of both the USB ports and plugs are incompetent at designing something industrial grade that locks down firmly.
SCSI cables were fine, their ports were secured to the housing and they had nice screw locks so the cables wouldn't go anywhere. Any cantilever forces were absorbed by metal casing, not PCB. Super reliable.