This seems like a dubious explanation; you can get quite high-quality external webcams that use USB 2.0.

I'd say a more likely (and harder to fix) explanation is that the phone ones can be deeper; laptop ones have to be very slim to fit.

It could just be a question of pricing. Maybe high quality phone cameras are available for very cheap, while USB 2.0 cameras with good image quality are not available for cheap from any vendors. There might not be any rational reason why this is beyond offer and demand.

Exactly. You want thinner bezel, slimmer Screen, and the trade off is simply the camera. Unfortunately there doesn't seems to be enough interest in it for Apple to innovate.

They could put a notch into the Macbook screen. /s

DO NOT GIVE TIM COOK IDEAS.

I guess Apple would be in a unique position here to use their experience from mobile to make a better integrated webcam in their computers as well, without most of those limitations.