You cover your phone camera? This only works on mobile and pops up the native Android/iOS camera which requires you to actually take the picture (and at least on iOS, asks you to confirm you would like to use the photo before going back to the website)
I habitually cover the camera on my phone when I'm not using it. It's just common sense for any connected device running complicated software without hardware switches to turn the sensors off reliably. The latter would be better of course but there wasn't a practical option for it last time I was looking for a new phone.
It's definitely a niche market at the moment. It really shouldn't be given the implications of connected devices, sensors like cameras and microphones, and where those devices get taken by many of their owners. I believe we would have a much safer and more resilient society today if the norm had become for connected devices to follow the principle of least privilege and for there to be complete transparency about how any kinds of sensors and any kind of remote communication operated. But apparently the market has spoken (even though in most cases it was only given one "choice" of what to say).