Yes, and TB5 also uses around 10x as much power, around 4W rather than 0.4W for USB3, which would consume the majority of the sustained power budget of the entire phone.
The point is, with your example the link speed of the iPhone isn't the limiting thing of your example. You'll likely be limited by the speed of your storage before you saturate that link.
You could argue most people wont need that speed, but most people don't need pro phone too.