It’s my understanding that mass produced items are all basically the same. If you buy something like a toothbrush, for example, then any other toothbrush from that same assembly line is going to be basically the same and have all the same specs (with the exception with minor defects here and there), because the machinery and process to make any those toothbrushes are all basically the same.
But that can’t be the case with locks and keys. Because if every lock and key were the same then there’d be no point in having them. Anyone could just bought the same key/lock combo could use it to unlock your front door. So all or most keys and locks must be unique. So how are they mass produced in a way that preserves their uniqueness?
locks arent useful majority can be broken with the right lockpick. Also they mass produce them with variations so that they dont work on another you would find it hilarious how easy one lock can have multiple key configurations by changing the math behind the pins and keys. It’s more to prevent someone doing it easy and just opening the door than an actual burglary. This is one of those inventions that prevents opportunistic behaviour
The utility of a lock is that it’s a clear permission barrier. If you don’t have the key and bypass the lock, it’s clear at least to you that you aren’t using a key. Which can be the difference between ordinary trespass and burglary.