Exactly. Why the fuck is it on at all times?

This isn't the 20th century. We get a LOT more deliveries these days, and a lot of them are expensive small electronics, like phones. They sit there on our front step all day , while we are at work, tempting porch pirates.

About the only thing keeping those jackals from stealing EVERYTHING, is the fact that they know there are cameras on the house, and also most of the houses surrounding the target. That scares off all but the most desperate thieves.

Peep holes are the most basic security precaution, but they are severely limited. They are distorted, and can be easily beaten by ducking. You may look out and see one guy, while three more are below the peep hole. They don't record, so there is no evidence to identify troublemakers later. They can't be accessed remotely, so you can't see who is messing with your house while you're out.

To extend your logic, we shouldn't use cars, because bicycles did the job just fine. Or phones, because we could just yell to our neighbors. Or stoves, because open fires cook food good enough. Or computers, because writing on paper always worked fine. For that matter, why use ballpoint pens, when a quill pen always worked good enough.

Why bother to improve?

Yeah, except if he knew everyone that entered the apartment at any time was recorded, it would maybe have been a deterrent.

Her other option could be a hidden nanny cam trained on the door so she'd have proof she wasn't crazy.

But again the issue isn't people wanting to know who is outside their door, or entering without their knowledge. The issue is the camera companies keeping all the footage for themselves.

We have an off brand camera aimed at our porch for porch pirates. It's not going to get someone walking by on the street. We have it only recording to the sdcard.

But we can live view and it alerts through the app. We don't use the cloud service or AI. But there's nothing stopping the app from screenshotting alerts and sending them somewhere.

I'm trying to figure out how to have an actual closed system so only computers under my control can access camera(s)

There are inside devices that could stop someone with a master key, like chain locks, but you have to be in the apartment. Once you leave, you obviously can't set the chain, and anyone with a master key, or is a good lock picker, can get in.

I've never heard of setting the bolt a certain way, except maybe in hotels. Even then, it only works if someone is physically in the room.