I don't see why a lifelong monopoly is required for the artist to receive the "full benefits" of their work. This discussion is about what legal options should be available to retain those benefits.

Here's the thing with copyright: it's a bargain between the public (IP consumers) and the authors (IP creators). The public wants new creative works and has recognized that some legal protection is needed to make these profitable, but when you share an idea and the public adopts it into their culture, it is no longer the author's thing. We grant a limited monopoly on copyrighted works so that authors can make a living and produce good stuff for us, and authors accept this aware that their publication will eventually into the public domain for free sharing, cultural commentary, etc.

First, it's important to recognize that a copyright is a monopoly. You don't technically need a copyright to make money -- it's just a temporary thing we provide to ensure that artists have ample time to recoup their investments. Original authors can continue to create products off of those IPs after the copyright has lapsed, and they can continue to sell and profit off of these; they just won't be able to stop anyone else from using the same IP.

Second, the need for authors to be profitable is well recognized today, but the other end of the bargain is neglected. Ideas are free and they do not belong to people. "Intellectual property" is really a misnomer -- ideas cannot be held or controlled like property can. They have a very different nature. If your creation gets any semblance of recognition, people will modify, alter, suggest, revise, expand, and otherwise build upon your ideas. When you publish something, it's not just yours anymore. Expansion and development and commentary are natural human activities that are impossible to prevent. Sharing and communication is everything to us, and copyrights restrict this free osmosis in a rather severe fashion.

Copyright is conceived to ensure an author can be profitable, so that more art comes out. Long copyright terms are seriously harmful because instead of encouraging new development from creative persons and/or those close to them, a successful copyright holder will be provided ample money for several lifetimes, and the monopolistic grasp that forces ALL revenue to go into their pockets propagates through the generations (right now, some copyrights could last 200+ years). Meanwhile, innocent parties attempting to expand on the copyrighted material and share in that natural human impulse for discussion and improvement, potentially contributing major social value to this cultural element, are hounded and threatened by aggressive lawyers. Does this promote useful progress in science and the arts? Does this represent the bargain that is meant to be recognized when a copyright is granted?

I don't think copyright should exceed 20 years. Ideally I'd like to see default 5-year terms with four optional 5-year extensions. This makes it so there is still plenty of opportunity to collect revenues that are beyond reasonable, but copyrighted material will lapse into the public domain sometime when someone still living will care about the contributions that others may make. It opens up a whole new world of cultural richness, encourages creativity in expansion of old properties and the development of new properties, allows the author to obtain huge financial benefit (which they can continue to compete for once the IP goes public domain), and is fair and courteous to the public's requirement that their culture not be held hostage by a bunch of suits (lawyers, executives).

Again, I don't see why we need to perpetuate the myth that one useful positive contribution should entitle the contributor to a lifetime of exclusive control and revenue. That is not fair.