I believe it's simply that their older SoCs do not support USB 3 because it has never needed it. And the base not-Pro models will probably re-use the last year'

I believe it's simply that their older SoCs do not support USB 3 because it has never needed it. And the base not-Pro models will probably re-use the last year's Pro SoCs as it did this year. My bet is the new Pros will use a new SoC, and then the year after base phones will re-use that SoC and have USB 3. Even when they re-used the iPhone SoCs for iPads, their solution is to add a separate USB 3.0 host controller, while leaving the client USB on the SoC USB 2.0: https://forums.macrumors.com/threads/ipad-mini-6-is-still-usb2-0-when-connect-to-mac.2313014/ https://forums.macrumors.com/threads/ipad-mini-6-is-still-us... . That didn't stop them from advertising it as USB 3.0 of course.