My previous HP Envy x360 had such a switch on the side of the laptop that would electronically disconnect the webcam; it would completely disconnect according to the system. Enabling it would show a new device being connected in `dmesg`.

Not a great laptop otherwise, but that was pretty good!

My envy x360 has that button as well and it even puts a physical shutter in front of the webcam in addition to disconnecting USB.