Why would I use a lightning cable when getting data on or off the device is faster over Wifi. It's kind of a trick question, why don't you use this slower protocol? See no reason to upgrade it no one uses it!
It really isn't a trick question. If your needs are 100% satisfied through wireless, why would you ever care? I suspect for the overwhelming majority of iPhone users, even if the wired option was infinitely fast they would never have used it. We're long past the days of an iPhone suckling on iTunes.
The exception to this -- and there are exceptions -- tend to be "pro" users. If you're actually using the iPhone for video production in any way, USB 2.0 is a brutal limitation, and has long been a noted annoyance when you're transferring massive video files. Lucky for those people they'll be Pro buyers and will enjoy USB 3 (and maybe WiFi 6E? Not sure if this was delivered).
