I looked it up, and it turns out you're right. Both the iPhone 17 and the iPhone Air use USB2.

USB3 was introduced in 2008 (!!!). That is 17 years ago.

I already wasn't interested in this tech, to be fair, but I've had to support family phones synchronizing/backing up over the cable, and even at full theoretical speed for the transfer, we're talking over an hour vs just under 7 minutes. Which, considering the flash most likely suppports the read in under a minute, is crazy.