The maths works out pretty well if you look at it as a marketing funnel for the author.
In the "traditional" model the author/publisher has to persuade a potential reader to part with money before reading the book, which has huge friction and costs lots of marketing money to persuade people that the book is good enough to buy before they read it - no "one month free trials" here. Using standard marketing funnel maths, they have to get the title in front of 10,000 people to get one sale (assuming a 1% conversion rate for the 2-step funnel). The net profit of this model is lower (for the author) because so much money is spent on marketing.
In the donation model, the author gives the book for free, and then asks for a donation afterwards. They only need to get 100 people to read the book (assuming a 1% conversion rate of people who have read it and want to donate). The cool thing is that those 100 people have read the book, and know it, will talk about it, will recognise the author when their next book comes out, etc.
If this work didn't have much value that would be one thing, but it clearly does. Otherwise people would not be clamoring for access to it. Nobody cares if crap is freely available.
People really want this stuff. They just don't want to pay for it either directly or via any public method. Meanwhile they spend the cost of a median price book or album in 1-2 visits to Starbucks without thinking about it.
There are all kinds of labor that people do with out being paid in currency for it, they derive other value from that labor.
You then present a false dilemma in that it is either copyright law or socialism (public funding), there are a whole host of funding models that have been proven to work over and over again that require neither. Open Source is a ripe with examples, YouTube also provides for some, but there are many others (including complete creative Commons books that are funding voluntarily, and voluntary "Pay what you want" systems)
It takes years to write a good book. Years. It's not something you just whip out.
The same applies to any non-trivial piece of music, art, software, engineering, design, or any other form of intellectual labor. People spend years and years on that stuff but only after they spend years and years getting good enough at their craft to actually produce it.
I guess there's another option beyond the two I cited above:
(3) Everything is low effort shit.
Open Source is almost entirely funded by large companies. Pick a popular FOSS project and look at who's committing to it. They're people being paid by large companies to do the work because the company has some vested interest in supporting it. The counter-examples are either SaaS driven (meaning they're not really open) or dual licensed (meaning they're using copyright law).
This sort of philanthropy has limits. In particular it doesn't work for consumer items, only for stuff that companies use directly.
I really don't think you want to bring up YouTube as it actually proves my point. YouTube is a cesspool of propaganda and divisive trolling. That's the kind of content you get when it's "free" and creators must find roundabout ways to get paid for it, such as by stoking society's divisions for attention to monetize ad views.
> It takes years to write a good book. Years. It's not something you just whip out.
nonetheless these works are freely available.
However, despite perhaps a few exceptions here and there (Kahn Academy is another), overall I very much agree. People have to be be paid. And while Patreon-type stuff is a great idea as far as it goes, it is not sufficient.
No one gets paid to "spend years and years getting good enough at their craft" of writing. Very few people get paid reasonably to "spend years and years on" writing a good book.
People who do intellectual labor, such as writing books, must be paid because everyone must be paid. Nothing is free.
There are two options:
(1) Copyright law, which allows them to erect toll booths and charge readers and users for their work.
(2) A socialist type of system where writers and other intellectual laborers are supported publicly.
The cyber-libertarian crowd is unhappy with both these options. They want everything to be free in all ways.
Since intellectual labor is not free, Jeff Goldblum's Law (from Jurassic Park) comes into play: life finds a way. The way to support oneself in the cyber-libertarian everything-is-free world is by either overt advertising or whoring oneself out as a propagandist (covert advertising).
A third variation also exists that combines aspects of both: surveillance capitalism. In surveillance capitalism all the free stuff is placed on a platform that spies on its users and the data is used to drive both overt and covert advertising.
This is why a simple news web site is 20+ megabytes of trackers, ads, and surveillance crap, and why every platform seems user-hostile. It's also why an increasing amount of intellectual product whether it be books, news, podcasts, etc. is actually political or other forms of propaganda. You can make money by shilling for political parties or political agendas. You can't make money by being balanced and honest and level headed. The work will be much higher quality but nobody will pay for it.