The LAN and WAN ports have an RX at 930Mbps, which is close enough for a $25 machine. The picture accidentally labels the LAN port with the USB speeds, which is a typo.
The iperf3 tests of ethernet speed put it on par with the RasPi4, and I suppose if the latter claims to be gigabit then all the competitors with similar performance need to as well.
I don’t own any friendlyelec devices, but they are a respected company. I used their picture (and not one of a Rock64 or Raspberry Pi, I do own those) because this one looks so much like the one deeperconnect is selling. There are other companies (like GL.iNET) that sell devices in roughly the same form factor.