This is one thing Apple got right a veeeery long time ago. Every screen they have sold since like the mid 2000s, both integrated and standalone, has had auto brightness. I don’t understand why other manufacturers still can’t that right, to this day, no matter the price category. Even most non-Apple smartphones these days still suck at this.
I’m surprised Linux doesn’t have some ubiquitous “use the camera to do auto-brightness” option (pinging the camera on a proprietary OS would be creepy, but if it is open source…).
That wouldn’t work very well because pretty much every webcam has auto exposure adjustment. Also a camera is good at determining how much light is in the room behind you, not how much light is hitting the screen. There really is no substitute for a photodiode and a halfway decent control algorithm. It only costs a penny so there really is no excuse not to include one.
I know a lot of people who have covered their camera with tape. Some laptops even come with a physical shutter. This is something company policy often recommends - if the camera is physically covered an attacker can't see the next product we are working on.
When I buy a laptop, one of the things I'm looking for is that it doesn't have an integrated camera at all. It's happened sometimes that I can't find one, then I cover the camera with tape.
The Lunar dev has a variety of recipes for a hardware widget you can build which allows their macOS-only brightness-control app to implement adaptive brightness on any monitor that permits backlight control over DDC/CI. I'm sure a more-motivated and clever person than me could tap into that hardware and use it to drive ddcutil/ddccontrol outputs on Linux.
