What are the biggest benefits of copyright for society?

The fundamental idea underpinning copyright is that it allows people to make a profit from their work, be that recorded video, audio, a written computer program, or any other kind of intellectual property.

If there was no such thing as copyright, if you recorded a music track and gave it to somebody, they could legally sell it themselves to other people, and undercut you or just give it away for free. (of course people still do on a person-to-person basis, but this would make it completely legal for even a movie theatre to show hollywood movies without paying any rights)

Why is creators being able to make money in this way from their creations good for society? Well, previously, the method to make money from art before copyright was the patronage system, which involved wealthy individuals sponsoring an artist to create things on their behalf, with varying levels of interference in the process. This worked to some extent, but the fundamental idea underpinning copyright is that if everybody sponsors a small amount for a product then it will be better for most people, rather than catering to the specific tastes of a single wealthy individual.

You see this kind of thing happening nowadays with platforms like patreon - it is possible to earn a living from a relatively small subset of the people that actually consume your content, and even while giving it away for free, simply because those people have a desire to see more of the same stuff. The problem with patreon is that it has to overcome a little bit of a tradgedy of the commons problem, whereby stopping your own individual contribution is unlikely to have much of an impact on the quality of art produced. Nonetheless, it seems to have found it's niche, and is only growing.

What about if nobody pays for art? There are plenty of parts of our culture that nobody got any money for. Often things created by relatively nameless folk expecting nothing in return but the love of creating are some of our greatest cultural works, be them folk songs or open-source software.

While I speak mainly about art and music in this piece, any kind of intellectual property that can be copyright works in mostly the same way. There is relatively little that is different in the grand scheme of things between monetising a song and monetising a coputer program - both are practically impossible to do without allowing the user to share it futher without your control.

Best case: There's an open source Quran app & site, done by people whose primary motivation is to use their tech skills as an act of worship. The more people use it, the more they benefit. The more people fork it, the more divine favor they get. A lot of people donate to the project, even though the team has no problem with server costs, etc.

But it's protected with a GPL-3.0 license. You can't just clone it, build, and sell it.

I think the base idea is that it's unfair for one person to spend years on a product and someone else to sell it. It's unfair for the people who have donated to the team that has built it.

The sense of unfairness prevents people from contributing.

The question seems somewhat biased, why is copyright assumed to be strictly beneficial? Of course it has benefits, but surely it can't have only benefits. Isn't a more honest question to ask: "What is the impact of copyright on society"?

This is a good start imho: http://web.utk.edu/~kperkey/reporthtml/benefits.html