I don’t want to end up having to have a specific cable for each
device, so I'm wondering if this is normal for USB 3.0 devices. What
kind of cables should I stock?
So the links to products you provided definitely only show USB A connectors on both ends which is definitely unusual. I have numerous USB 3.0 drives and the all have an A connector on one end and a B connector on the other end. But USB 3.0 cables are definitely not like a standard USB 1.0 or 2.0 cable. So if your goal is to avoid carrying specific cables for specific devices, you will still have to make sure you have a USB 3.0 cable of some sort since there are 5 additional connections that need to be made for a USB 3.0 connection.
These images from Wikipedia show exactly what the pinouts are on the connector; 1-4 are basically USB 1.0/2.0 equivalents, but 5-9 are where the USB 3.0 magic happens. So in general USB 3.0 cables are completely different beasts from USB 1.0/2.0. Whichever way you look at it, you’re going to have to add at least 2 more cables anyway to the stuff you carry around if you want to make sure that all bases are covered.
Here is a USB A connector:
And in my experience, more and more USB 3.0 devices are using the USB 3.0 Micro-B variant; note the extra connections right next to the standard micro USB connection:
But a USB 3.0 standard B spec exists and it looks like this; note the extra connections on top of the standard micro USB connection: