"And if you are really interested in this topic, I suggest you read about the history of copyrights"
Been there, done that. You left a few details out, like how the first copyright law, the Licensing of the Press Act, was passed to enforce censorship, and how the next iteration was passed following heavy lobbying pressure by the printers who had enjoyed the monopoly position they held under the censorship program. The idea that copyright began as a way to pay authors is based on ignoring the Licensing Act and based on ignoring the role that printers played in pushing for the Statute of Anne.
The arguments authors made in favor of copyrights in the 18th century would have amounted to nothing were it not for the business community.
Prior to copyright, you had Shakespeare, you had folk music (which was spread peer to peer), and you had other modes of entertainment. Nobody was wanting for music or comedy. Written entertainment was more limited by the poor literacy rate of the general population than by the lack of written works. The biggest problem facing actors in 16th century England was not the lack of income (despite the easy duplication of a play), but the fact that they were often arrested as vagrants, and the general trouble with having secular theater at a time when religious institutions were fighting to stay relevant (sound familiar?).
Numbers are unfortunately hard to come by. On the other hand, you can find many shelves of centuries-old songs that were recorded by modern singers -- and it is not unreasonable to say that those songs are just a fraction of what people were singing centuries ago (society tends to forget songs, stories, and games over time). I do not think it is wrong to suggest that there were not shortages of music in the 16th century.
"not allowing for the "misunderstood genius" of people, but solely promoting popular content"
Copyright has done little to alleviate that. Misunderstood genius does not pay the rent; only popularity gives artists enough income to make ends meet on royalties alone. Authors, musicians, and actors frequently stick to their "day jobs" just to pay rent.