Yes; royalties are one way of ascribing value to intellectual property.
They were used to make money for their owners.
Only if the copy you're copying was not authorized for general distribution by the copyright owners. In other words, the copyright owners can certainly authorize free distribution of their music if they want to. However, if you make a download (a reproduction) of an unauthorized copy, then your copy (like the one you copied) is a copyright infringement because you have no permission to make that copy.
yes
win money
6.305 Million Dollars plus royalties
It depends on your relationship with it. If copyright is the way you make money to feed yourself, it's pretty darn important.
A business holding a copyright on something can prevent others from abusing it, and make money by licensing its use.
to make money.
so they can collect the money
Slave owners made lots of money but no one knows exactly how much money they made
Not much because she doesn't write a lot of her songs, therefore she cannot get publishing royalties. Some of her songwriters are Dr Luke and Taylor Swift. They'd get the royalties there. Miley has many other ways of making money though like selling records, tours, merch, tv etc...
One can make money off copyright by licensing their work to others for use, selling their work to publishers or distributors, or by enforcing their rights against those who use their work without permission.