The new iPhone 15, iPhone 15 Plus, iPhone 15 Pro, and iPhone 15 Pro Max all support DisplayPort for up to 4K HDR video mirroring and video output to...
Those aren't contradictory. DP is via connection to GPU using the high speed lanes and the 2.0 USB is from the A16 chip, which was designed with USB2.0 over lightning in mind from my understanding.
For people who don’t know, a “lane” in this case is a literal wire on the cable. You can have multiple lanes that have separate protocols, e.g. a lane for audio, a lane for DP, a lane for USB 3.
IIRC there are always lanes for USB 2, and USB 3 speeds are achieved on separate lanes. Thats why all USB-C cables and devices must support USB 2.0.
You said something I didn’t even think about: The a16 in the iPhone 15 is last year’s chip. Of course it doesn’t have usb 3.0 or anything else, just the 2.0 speeds it was designed for.
I do wonder, however, if the A17 will retain the new updated usb feature that the A17 Pro has (clearly they’re binning something or other)
USB3 is at this point 15 years old and USB2 predates iPhones completely. Not sure how that is understandable and/or acceptable. It also has nothing to do with main chip, since IO chip is separate.
The IO chip is separate in some of their tablets (apparently there's an old ipad air with a14 that has a separate IO chip to support 3.0), but I think for phones apple typically groups them together.
Kinda sad apple continued using lightning with usb 2.0 just to maintain their proprietary interface and didn't even both upgrading it.
Because they take last years "pro" and shove it as this years regular. Half of the work, double the sales. This time they had to adhere to USB type C because of EU regulation, so they glued connector to outdated IO chip and made it work just barely.