Why go through the trouble of writing a better Harry Potter? You could simply take the existing story and sell it yourself - or put it on the internet so that no one needs to buy it at all.
I agree that it might be beneficial for society if all media were available for free and I agree copyright is probably not the right tool, but that's why said more thoughts effort needs to be spent to find better alternatives.
In the 19th century, America didn't respect British copyright. And Charles Dickens was the most popular writer in the US and was printed there without paying Dickens a cent. So how did Dickens handle this? By going on tour in the US. People paid money to see him recite his works much like music concerts. In fact, this is how most professional musicians make money today in the post physical album world. They don't make much money off their music directly but rather the music serves as advertisements for their live shows.
I agree that it might be beneficial for society if all media were available for free and I agree copyright is probably not the right tool, but that's why said more thoughts effort needs to be spent to find better alternatives.