Laws and regulation
Many countries actually have laws and regulations behind paywalls. This is incredibly stupid. If you don't know what laws there is, you can't follow them. This also makes it more difficult to start small businesses.
Science is a big one. Scientific research is mostly hidden behind paywalls. Each post has roughly 10-50 sources, which is also behind paywalls. Then those have 10-50 more sources. Lets imagine each scientific paper costs 30 dollar on average and has 25 sources on average.
- Checking all the sources for the paper would cost: 750 dollar.
- But to check the sources, sources would cost: 18750 dollars
- Lets say the average line to find the data of the source is 5 hops. Fact checking one single scientific paper would cost: 292 968 750 dollars.
Obviously I'm being hyperbolic. It's not really that expensive and papers with to much flippy floppy sources, won't get peer reviewed in the better journals on the master journal list.
A lot of people give their time freely to create free educational resources for their students. What often happens is that people who wants to make money go around schools to collect this material, filter trough it and publishes it under copyright in their own names. The motivation to create and share free education, is so large I can't understand. Why do people want to post school material under copyright and how is it still economically viable. In particular material for kids?
Entertainment - Movies and Music.
This one I understand, but it's still overpriced. People generally can't afford to watch movies as their hobby. Luckily this is improving lately. Free legal entertainment, has actually started to out compete with paid entertainment. So the change had to come and will have to go even further. Youtubers are stealing the markets of the old media.