I was trying to come up with a reasonable solution this. I wouldn't trust any software solution in the OS that "disables" the camera because even if hacking of the device is not possible, some sort of settings-phising might be.
It seems that the only way to deal with this, would be to have a hardware switch that disables the camera, e.g. like iPhone's mute toggle.
But the OS can still get hacked to ignore the state of your toggle. E.g. the iPhone’s mute toggle doesn’t stop the alarm clock from using the phone speakers.
It's been a not-unusual practice among privacy&security people for a long time.
Starting around 20 years ago, hackers spying on people through their webcams was publicized (such as with the cDc's Back Orifice, IIRC). For a while, webcams sometimes had physical doors/shutters over them. More recently, there was a boost of awareness, when Zuckerberg was seen covering his own camera.
But some companies presumably wanted you to be accustomed to their proprietary-ish videoconferencing, or to be accustomed to large wireless data plans, with network effects, and so they perhaps wanted to encourage front-camera use. Also, a door/shutter doesn't look sleek.
(Next time I have a physical office, I'll probably hang a little basket outside it, to give away trimmings of black and white labelmaker tapes, for this camera-covering purpose.)
