I think you will have some trouble finding a decent 2 or 3m long cable for USB 3.1 gen 2 cables.

Section 3.1.2 of the USB type C spec states that the max cable length supported for USB 3.1 Gen2 is 1m. This is largely limited by the additional capacitance of the longer cables.

It may be possible to go longer with an active cable, but USB type C active cables require the device to support USB power delivery and Vconn to power the cable. So even if you had the cable, you would need to make sure the device you are using it with is compatible as well.

Probably a little more detail than you wanted, but that may be why they are still hard to find.

I did find someone advertising a 10Gbit/s cable. But turns out it's not compliant with the standard and is actually a USB 2.0 cable.