Cameras in phones are pretty much locked up today, assuming you have an updated version of the OS from a respectable manufacturer. Apps will not be able to access the camera feed (or the microphone) without explicit consent and a visual warning.

The manufacturer might access it, Apple states they don't, Google and Samsung I'm not sure. A bad actor with 0days might too.

It is funny since I wonder when you're looking through say the Google Feed (swipe left on Android devices on home screen) does the camera track your eyes, what you're looking at

It does seem harder to tape the phone camera since the in/out motion into your pocket I imagine would remove the tape.

It's harder to tape it when it's now a small island in the screen.

Laser engravers. Blu-ray drive laser modules are dime a dozen and are plenty powerful.