With a 28 year copyright term (14 years, renewable for another 14), the way it was in the early 1700s, Forrest Gump would just be entering the public domain.

That seems about right. They've made their money. It cost them $55m to make, they've made $650m on it so far. And anything that's going to come in in the future is going to be a trickle compared to the first few decades of the movie. It also seems about right because Forrest Gump has become part of the culture. People quote lines from it. It's used in memes. It has its own life that lives on outside of the IP owned by Paramount.

But, because of the warped copyright system, it won't be in the public domain for nearly another century.

The purpose of copyright is that it's a balance. It incentivizes artists to make things, and in exchange those things enter the public domain a short time later. Without copyright, the theory goes that artists won't create as much art, so fewer things will enter the public domain.

But, can anybody argue, with a straight face, that unless copyright terms are 120 years, Disney and friends just aren't going to bother? Do they really need more than a century as an incentive, and as a way to recoup their costs? Of course not.

The worst thing is that other countries used to have slightly more sane copyright systems, but the US imposed the ridiculous US system on most of the world by strong-arming every other country into agreeing to copyright treaties, that force these other countries to essentially adopt the US system.