> That's security by obscurity

Exactly. And in instances of securing physical objects, depending on the threat model, obscurity can an effective barrier.

Yeah, obscurity seems to help in the real world. The Presidential motorcade has a bunch of identical limos so attackers don't know which one the President is in. They, of course, have armor too. But the decoys add to the security, even if it's "by obscurity".

Sure, and don't lock your door since a smashed window is always an option.

The content gets stolen either way. You would save the money on window repair at the cost of losing a small deterrent (maybe a thief would refrain from making noise)