I think the underlying philosophical idea of copyright is good.
Is it? But first, what do you mean by the "underlying philosophical idea"? If you mean "People who create good new things deserve to be rewarded", yes, with that, I agree.
The idea of copyright is that the right to copy, which is a Natural Right, should be taken from the public by government fiat, so that a system of compensation can be hung on handing that right back out in a very limited and controlled way. I very much disagree with that. It worked somewhat when copying wasn't so easy, when the printing press was the state of the art for disseminating news, info, and entertainment. The advent of AM radio, which was bitterly fought by the entertainment industry, forced a number of changes, culminating in the business model of making money through advertising revenue, and passing some of that on to the artists in the form of licensing fees and royalties and so forth. FM radio and TV followed that model.
Disruptive though radio was, it pales in comparison to current tech. Radio did not upend many other kinds of media, such as print. That is happening right now, with the advent of the Internet, and mass digital storage, and the means to read and copy that storage at unprecedented speed and quality.
Think how much better our handle on the accumulated knowledge of civilization, housed in libraries public and private, could be, if not for copyright. Vastly larger selection. Far, far greater storage density, with an entire wall of books that might weigh a ton, replaced by one flash drive that weighs a few ounces and can fit in a hip pocket with room to spare. Searchability to put the old card catalogs to shame. No need to physically transport media, traveling to and from the library. No more book return hassles. Far greater data safety, far fewer losses from damage or destruction of media. Errors more easily corrected.
That we are expected to not use those fruits of our new technology, solely to prop up a traditional business model that never was all that great to begin with, is hugely costly and unfair. Every second that we could have had high fidelity scans of famous works of art, such as the Mona Lisa, The Night Watch, Starry Starry Night, and The Scream, but didn't, because rights, is a second in which we risk the permanent loss of another piece of our history. Yes, those paintings are long out of copyright, yet somehow, private collectors believe that if they wish, they can assert that the public still doesn't have permission to photograph their "property". Every time a museum collection catches on fire, or burglars steal the only copy, we lose a little more. We have the means to make such losses a relic of the past. But, "rights". It's nuts.
What I envision is a future in which downloading is good. Yes, please download the latest Disney animated movie, from anywhere you like. We shall have new systems in place to ensure that Disney is fairly compensated. For these systems, I am thinking that patronage, especially in the form of crowdfunding, is the way to go. This is what the entertainment industry should be doing, building up crowdfunding and patronage systems, not idiotically fighting rearguard actions to cling to copyright.
One thing that is not much appreciated or recognized now, but which I think in the future will be, is just how much ownership thinking infests and warps our art. Examples abound, from the blatant as seen in the Star Trek episode "I, Mudd", in which the writers have the characters engage in a little dialogue in which the penalty for violating intelllctual property rights on the planet Deneb IV is revealed to be Death (yeah, they wish!), to the much more subtle in which copying is inexplicably hard to do, and therefore every loss is the more poignant, dramatic, and damaging.
Fantasy is particularly bad that way. Magic items are often imbued with a magically perfect sense of property rights, so that they only work with the "proper" owner. For instance, the Elder Wand in the Harry Potter books won't function fully for anyone except the one person who "won" it properly from the previous owner, because, why? Because it is somehow sentient and has this enormous respect for property rights? And in Lord of the Rings, what enables Gandalf to resist the temptation to take the One Ring? His respect for ... property rights?? When he is freely offered the One Ring, he begs the Ring Bearer not to tempt him that way, seeming to fear that avenue to corruption more than any other. Weird. I hope you begin to see what I mean about so much of our art being warped by this kind of ownership thinking.
However it is SF that is the worst at clinging to ownership of the immaterial. There are many SF stories that delight us with a future full of incredible technological advances, yet somehow intellectual property law has not changed a whit since the 20th century. Star Trek again, posits this future in which we can go zipping around the galaxy with faster than light travel, and our society might not even use money any more (but then, for what stakes are they playing, when they play poker?), yet, somehow, Mudd got in big, big trouble for copying a few ideas. Another bad one on that front is the SF novel Hyperion, in which one of the characters is a famous author, but was screwed out of all kinds of royalties because the AI community bought just one copy, and shared it amongst themselves, with the publisher commenting that "copyright doesn't mean s*** with silicon".