Growing trend in a niche market I would suggest. I know people who have 2 laptops - one for gaming, one for work (with webcam etc). Because the gaming laptop is too bulky to carry around, it's effectively a desktop.
if you are a gamer, you don't use a laptop. Gaming laptops are great portable desktops effectively. They have little autonomous time gaming or heavy compilations. So they have to be plugged in - they still are not great as a desktop gaming station, though.
I personally use a 'gaming' laptop as the default work computer (it's over 3.7kg w/o the charger which is another 600g)
It's a growing trend ... if you're a gamer who spent 2000$ on a laptop and also want to do some remote work/interviews you need an external webcam...