Right now my webcam (built-in) is "disabled by wire" by me since I never use it. Were I to use it but want to prevent unauthorized use I would simply craft a small flip cover that I kept in place over the lens except when I use it. Given that my microphone opening is the size of a pin hole I would be covering that were I worried about unauthorized activation, but I'm not.
Even I have two autohotkey scripts right now, one of them toggles the webcam driver & the other mutes/unmutes the microphone. The problem with this setup is that I have to REMEMBER to disable it after a call. There's a lot of room for human error there, thus not the best solution there can be.
Why would you be suspicious of programs that you have installed yourself over time? It is not in the best business interests of any commercial application developer to spy (and surreptitious activation of camera and/or microphone counts).
A lot of them are closed sourced programs & I wouldn't disagree that the chances of them spying are rather unlikely but I need such a program as a safety measure in case it happens because if it happens there would be no warning. It's a case similar to why I have my AV installed. I haven't gotten a real malware on my PC for 7 years, but removing my AV just because of that would be unwise, since I can't know what kind of threats I may encounter in the future.
Have you ever had anything show up in Micro Snitch on the Mac that was unexpected?
No, I don't own a Mac. During my search, that was the program that did exactly what I wanted, so I used that as an example. I already have a similar setup on my Android phone, wanted to do the same for Windows.