A copyright isn't owning a car, a copyright is more akin being the only person legally allowed to manufacture cars. (This isn't hyperbole, a patent on cars is control of the very concept of cars; copyright and patents are more similar than dissimilar.)

That's why it was supposed to be a limited right with a clear and simple expiration. No one should own the concept of a car forever, eventually you want other people to be able to manufacture cars.

That's why it is a monopoly right.