Why is renting DVDs still a business, even though it's obvious people can rip DVDs with their PCs?

DVD’s can be ripped easily. They have DVD’s at video stores and libraries .. Anybody can check them , rip them, and nobody will know.

But it’s obvious to everyone now in ths digital world, that it’s easy to do. And yet( i haven’t been to a rental store in years) correct me if i’m wrong, but none of those DVD’s and CD’s have any protection against ripping them.