Although years later from the discovered exploitable vulnerability with iSight's LED, I am wondering if the issue has been fixed on 2019 and 2020 iMacs and Macbook Pros. Can the iSight LED still be overridden through software, or is it actually hardwired this time so that the webcam cannot turn on unless the green LED turns on too?
From a practical stance, macOS now blocks all apps from the camera in software so you can easily know all apps that could even request access to the microphone or camera.
In 2009 the firmware of the hardwired cameras was secured with encryption. I haven’t seen a credible report that this is broken, but depending on your threat model, you might close the lid if you can’t trust Apple to secure things.
Whether you trust the LED auto-functions and cannot fail as an intrinsic part of the operation would need to trust someone who can forensically examine the hardware (likely destroying it to be certain how it works) and assuming all are made the same.
I think you the camera is the least revealing or worrisome part, but it’s fine to question and learn even if it’s a small risk or no risk or you have easy mitigation options.
Also, all Mac cameras are hardwired. Just the security is far better hardware wire since 2009 and software side many steps better but with SIP and Catalina it’s really a hardened target for the software to get compromised.