Earlier quoted context omitted.
Most people gladly opt in to use their webcam for Zoom.
That's the key feature. That's why they're using the product. I opt-in to using my car to drive, and I opt-in to using my laptop to write code. I don't opt-in for tracking, advertising, or other negative externalities.
And I don't even think it has to be the primary feature. As someone else mentioned about maps, map apps are still plenty useful without location tracking (indeed, analog maps worked well for millennia without it), but I know if I opt in to location tracking while using a map app that I'm going to get a lot of additional useful features, so I do it.