Like the YouTube video creator, I also notified Anker of the same issue.
This cable cannot give 3A in a typical USB-A to USB-C connection due to the 56k pull-up resistor. The resistor is literally designed to limit power output in a type-A connection. That's why he has no issues when using a type-C to type-C connector. Anker maybe implemented a proprietary logic (like PowerIQ 2.0) that overrides this, but they haven't been able to explain under what scenarios this cable can offer 3A in my latest email back-and-forth.
I think the marketing department needs to have a longer discussion with the engineering department.
I did note they updated the Amazon description to confirm the presence of the 56k pull-up resistor...but they still somehow still claim 3A.