I can't help but feel today's absurdly draconian copyright laws and lengths are going to make our century a terrible cultural black hole for our future-human descendents.
The vast, vast majority of creators who produce culture--books, movies, music, visual art, etc.--don't see widespread distribution, success, or fame in their own lifetimes. This is true today and it was true in the past too.
Today, we have people like Project Gutenberg, the Internet Archive, and others, volunteering their time and energy to lovingly archive, curate, and distribute out-of-copyright works. Many of these works get a cultural second life: people today can freely discover and read a book published before 1923, whose author might have died penniless and unknown in their day. Their work, their name, their ideas, and their legacy lives on 100 years after their death, even if the world they lived in overlooked them, because volunteers can freely update and distribute those works.
Can we say the same about the vast majority of work produced today, for whose creators don't attain widespread fame or cultural influence? Everything anyone produces, from a smudge on a piece of paper to the Great American Novel, now automatically gains a copyright that can last over a century, and that has almost never failed to be extended. As one of the many everyday creators who never see significant success, how would you feel if your work was not only ignored today, but for all time too?
Our future-human descendents are going to think culture from 1923-2100 consisted of almost nothing but the 400 comic book movies, the 75 Star Wars movies, and Harry Potter. Everything else will be too unprofitable for a megacorporation to distribute, and illegal for anyone else to.