I don't understand why marginal cost going down causes copyright to make less sense; I'd argue it now makes more sense, as creators can more easily lose out.
Copyright is intended to incentivize people to create things by giving them a limited monopoly on the ability to copy/distribute it. I write a book, no one else can print and sell copies without my permission. Thus I have a chance to make some money off it. If I write a book and anyone can sell it, I'm less likely to make money off it.
If that argument was true in 1800 when some other guy had to physically print out my book, why is it somehow not true today when you can upload a torrent of it?
(I do think current copyright terms are absolutely absurd. If they were 10 years or renewable with fees or anything else that would solve 95% of the problems.)
Because in 1800 someone had to spend some money making copies. If you have no copyright back then, the argument (albeit wrong, in my mind) would go that you needed the monopoly power to stop your published works being immediately undercut by bootleg copiers, because they did not have the upfront costs of actually producing the novel material.
In practice, even that explanation reflects on the insanity of copyright, in that you should never get to the point where you have done free work and now need the state to assist you in making a living off it. You should be seeking compensation for the act of creation, not for the act of copying.
For the same reasons people habitually treat fan works as independent from commercial ones, today people are doing the work for free when in the 18th century you could make a business out of duplicating others written works for profit.
Today, while counterfeiting markets like that still exist in less Internet-rich countries, once you have the Internet, the only thing such markets still apply to are novel physical inventions, and that is never done by small entrepenurs stealing other peoples work, it is by large corporations using economies of scale to produce replcias of a novel product that can undercut the original creator.
Because there is an important distinction between goods and information. A good is valuable for what it is - a fridge because it cools, a car because it can move on roads. The utility is in the physical atomic composition of the product. With informational works, which is what copyright applies to, the value is exclusively in the encoded information - you can transfer it in myriad forms, from light to electrons to magnetism to etchings on a wall, but in those circumstances the media of transit is much less relevant than the material itself.
It was only when the transit material was itself scarce that the argument for copyright was made. When transit becomes so cheap it is effectively free where millions will send you a copy for no charge, the assumptions are broken.
Once again, your entire argument hinges on forgetting that there is a cost to creating the material in the first damn place. And the way you recoup those costs today is to sell copies of the work. The transit method isn't relevant, because the purpose of copyright was to allow the creator to recoup costs in creating the work, not in selling it.
Copyright is intended to incentivize people to create things by giving them a limited monopoly on the ability to copy/distribute it. I write a book, no one else can print and sell copies without my permission. Thus I have a chance to make some money off it. If I write a book and anyone can sell it, I'm less likely to make money off it.
If that argument was true in 1800 when some other guy had to physically print out my book, why is it somehow not true today when you can upload a torrent of it?
(I do think current copyright terms are absolutely absurd. If they were 10 years or renewable with fees or anything else that would solve 95% of the problems.)