It says that it has four 10 Gb/s USB ports (2 Type A and 2 Type C).
It is unknown whether the ports are independent, or some of them or all of them are connected to an internal hub.
Even if they were connected to a single CPU port through an internal hub, if you used two 5 Gb/s USB Ethernet interfaces you would get close to full speed for them.
Having 10 Gb/s USB instead of the so-called "5 Gb/s" USB (in reality 4 Gb/s), provides much more additional I/O throughput than having 5 Gb/s RJ45 instead of 2.5 Gb/s. I agree that having 5 Gb/s Ethernet would have been nice, but it is much more valuable that it has 10 Gb/s USB, which is very rarely encountered on Arm-based computers.
10 Gb/s Ethernet interfaces work fine on 10 Gb/s USB.
Both interfaces have almost the same raw bit rate (in both cases "10 Gb/s" is only an approximation, but the differences between the true bit rates and 10 Gb/s are negligible, unlike for "5 Gb/s" USB, where the data bit rate is only 4 Gb/s).
The USB protocol has a slightly higher overhead than the Ethernet protocol, so the throughput of an Ethernet 10 Gb/s interface attached on 10 Gb/s USB will be a little lower than that of a PCIe NIC, but the difference is negligible, of only a few percent.
Unfortunately, USB does not work like Firewire, where this was possible.
USB 4, i.e. Thunderbolt, allows the emulation of network interfaces if you interconnect the USB Type C ports with a cable, but here you have USB 3, so this does not work.
On USB 3 you could interconnect 2 ports only if one of them implemented the On-the-Go specification, so it could work as either a peripheral port or a host port. Here this also does not work. On a system where this had been allowed by the hardware, it is likely that you would have needed to write yourself a device driver that emulates a network interface, because I am not aware of an already existing one, unlike for USB 4.
USB 4 includes more than Thunderbolt, because Thunderbolt was not compatible with USB, despite using the same connector.
All features of Thunderbolt 3 have been inherited by USB 4, like also all those of USB 3, including the ability of Thunderbolt to emulate Ethernet interfaces when you interconnect 2 computers with a cable through their USB 4 ports, like it was already possible with Thunderbolt ports.
It is unknown whether the ports are independent, or some of them or all of them are connected to an internal hub.
Even if they were connected to a single CPU port through an internal hub, if you used two 5 Gb/s USB Ethernet interfaces you would get close to full speed for them.
Having 10 Gb/s USB instead of the so-called "5 Gb/s" USB (in reality 4 Gb/s), provides much more additional I/O throughput than having 5 Gb/s RJ45 instead of 2.5 Gb/s. I agree that having 5 Gb/s Ethernet would have been nice, but it is much more valuable that it has 10 Gb/s USB, which is very rarely encountered on Arm-based computers.