The video does not support the notion that USB is sufficient for video out. You'll note that the connection is between the iPhone and AV jacks, not USB. While the cable features a USB port, it is not used in the demonstration for the purpose of outputing video.
The iPhone's data connector is not USB. It is a 30 pin connector and from some googling, USB only uses up 4 of those pins. This data jack is capable of much more than USB.
If your statement is that you do not need Thunderbolt for video output on an iPhone, then yes, that is true (the proprietary connector can do it when converted to AV or HDMI). But if your statement is that you can do it with USB, that is not necessarily true and theoretical numbers would suggest it does not.
The AOC monitor is dubious. To my knowledge there is no standard for USB video displays, which means AOC has to write their own drivers for this display. Being a vendor supplied driver, data does not need to be sent over USB in a raw form. It is possible that they rely on compression and have decompression hardware in the monitor. But see my error below:
I did make an error in my calculations and should correct it. I made the same mistake of treating bits as bytes.
1080p bandwidth reqs: 1920x1080x24x60 is only 0.37GB/s, not 1GB/s. So yes, 1080p falls well within USB 3.0 spec. The AOC monitor could very well be USB 3.0 and not rely on any compression tricks.
Whether it should be done is another question.
Thunderbolt being compatible with DisplayPort means that it supports an existing video standard. USB does not.
USB is host driven, which is potentially CPU intensive and not ideal for battery powered mobile devices.
It is also questionable whether USB can actually attain its theoretical maximum speeds. I think a review of existing comparisons between Firewire and USB 2.0 would demonstrate that Firewire is superior in terms of actual bandwidth. Firewire like Thunderbolt is driven by dedicated controllers, not host driven.
Also, keep in mind that you're talking about USB 3.0, not 2.0 (2.0 is inadequate for video out as we're discussing). USB 2.0 is an entrenched standard, USB 3.0 is not. When Thunderbolt and USB 3.0 came out, the two were widely compared. This is a battle to see which will become the new standard (i.e. more widely adopted) for high bandwidth applications (and that includes video output). Apple is very much in the Thunderbolt camp at the moment, so it makes sense that they would add it to their iOS devices. Apple does not currently support USB 3.0 as a standard.