Hi Garry and Kristi,
I don’t know much about USB transmission speeds. I assumed that a higher number means faster, and Wikipedia agrees with that.
I used a 10 foot cable for my connection, and you may have purchased a 10 foot lightning to USB cable. When I searched for such cables on line, most did not list whether they met USB 2.0 specs. I am pretty sure that the 3 foot cable that came with your iPhone 8 would be a 2.0 cable, and you could compare the speeds of different cables.
My way to quantitatively test speeds is to use https://www.speedtest.net. They also have an iPhone app. I suggest you do 3-4 speed tests with a cable and then using the wireless connection, and let us know what you find. The speed tests give you download and upload speeds, and for most people the download speed is the most important. Be sure to use the same server for each speed test.
Finally, it is possible that the USB port on the WiFi Ranger does not support USB 2.0. I have had great support from WiFi Ranger, so you could ask them. Edit: The WiFi Ranger web site says that the SkyPro model has a USB 2.0 port.