Or you can just bake the functionality into the webcam itself (like apple) and a cheap commodity item becomes complicated and expensive.

You'll need a special firmware for the cam (like apple device), need to ensure integrity of the said firmware and also need a customized driver which needs maintenance work.

I have an old Logitech Pro 9000 camera with a lot of bells and whistles but, when I found out that its light can be managed by the driver and the UVC client in Linux AND it can turned off while it's recording, I've never kept it connected longer than it should be.

So yes, custom and secure hardware is hard.