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?
When you buy keyed doorknobs and deadbolts, there’s sometimes (always?—not sure, but def sometimes) a sticker on each package with a code. This lets you look through the available inventory to find and buy additional locks with the same code so that if you need multiple locks for the same house, they can all use the same key.
So no, as others have said, mass produced locks aren’t unique, but sometimes that’s a benefit.