I have a 16 Pro so I’m not upgrading this year but if I bought an Air, I wouldn’t care about the USB 2 speeds. In 10+ years of using iPhones I’ve never transferred data off an iPhone using a cable. In my case I literally could not care less about the USB 2 limitation. And if I don’t care, it’s not a stretch to say that the vast majority of people will not care. Most people simply don’t know the difference between USB 2 and 3. People here commenting on MacRumors are not like the average consumer.
For some people it will be an issue. They’ll need to decide if it’s an issue they are willing to work with.