>I don't understand why this is a movement that is ethical to get behind.

Because we broke copyright. There is room to quibble about exactly where and when, but the result is quite clear. The best summation I know of is from a speech by Thomas Babington Macaulay in the British House of Commons in 1841[1],

"At present the holder of copyright has the public feeling on his side. Those who invade copyright are regarded as knaves who take the bread out of the mouths of deserving men. Everybody is well pleased to see them restrained by the law, and compelled to refund their ill-gotten gains. No tradesman of good repute will have anything to do with such disgraceful transactions. Pass this law: and that feeling is at an end. Men very different from the present race of piratical booksellers will soon infringe this intolerable monopoly. Great masses of capital will be constantly employed in the violation of the law. Every art will be employed to evade legal pursuit; and the whole nation will be in the plot. On which side indeed should the public sympathy be when the question is whether some book as popular as Robinson Crusoe, or the Pilgrim's Progress, shall be in every cottage, or whether it shall be confined to the libraries of the rich for the advantage of the great-grandson of a bookseller who, a hundred years before, drove a hard bargain for the copyright with the author when in great distress? Remember too that, when once it ceases to be considered as wrong and discreditable to invade literary property, no person can say where the invasion will stop. The public seldom makes nice distinctions. The wholesome copyright which now exists will share in the disgrace and danger of the new copyright which you are about to create. And you will find that, in attempting to impose unreasonable restraints on the reprinting of the works of the dead, you have, to a great extent, annulled those restraints which now prevent men from pillaging and defrauding the living."

1. https://yarchive.net/macaulay/copyright.html

I use AA and buy books. Typically I may start a series on AA epubs then buy the books. Sometimes authors take money directly (patreon, straight donations, etc) which is how I would rather pay them than pay the publisher for them to only get a small cut.

Are libraries unethical to use? You can go to your library and read books without paying for them.

Books worth buying usually have rabid followers who will buy them.

There's been a reasonable amount of research that suggests that piracy doesn't really cannibalise sales from those who can afford to pay.

But I do agree that for some of their categories a time wall would improve their optics.

I agree, but also you can't wait until something is out of print/unavailable to preserve it. Trying to prevent access to it or limit distribution will probably just result in it being lost media one day.

There's also the fact that just because a something is available to purchase in one country, doesn't mean it's available in other countries. A lot of movies/books/games/etc are geo-restricted in sale, with many countries having no valid methods to acquire them.

The best (but unrealistic) solution would be for people who can purchase legally to do so, while leaving it available for download for everyone else.

You can't just start preservation "when the books are no longer for sale." It has to happen asap, there's no telling when something will get harder to find.

Personally, having to buy the barely-changed newest yearly edition of half a dozen $300 textbooks per semester of undergrad totally radicalized my view on copyright.

Piracy never stopped the music industry, and the folks who were harmed the most by music piracy were the poor, cash-strapped billion-dollar corporations whose entire operating models already depended upon sucking wealth out of the actual, struggling artists who do all the work.

And it seems that piracy has become a net benefit to new and niche artists. (https://www.sciencedirect.com/science/article/abs/pii/S01676...)

I'd posit that the book industry will turn out to be the same. Piracy will harm the bottom line of the companies already at the top while giving exposure to the authors at the bottom. The latter being the ones who often strong-armed into terrible financial deals just to gain access to book-industry's four big gatekeepers, and who likely need that exposure to help keep a roof over their heads.

Anecdotally, I'm one of those folks who end up purchasing many of the books I pirate or otherwise obtain for free, and I'm sure I'm not the only one who does this.