Copyright law still benefits people. There'd be no GPL without it. Also, without copyright laws there;d be far more draconian DRM. Remember back in the days wiith custom floppies with laser burns that couldn't be copied without both a PC Tools option board (special floppy controller) and software that would allow the board to maintain a copy of the unreadable bits and return errors when those bad ones were read, or when they would intercept write requests and return just the bits that were readable on the original floppy?
Heck, I did something similar with a needle - just pierce a hole at random, then figure out which sectors are unreadable in my original. If you could read them, the floppy was not an original. And since it was at random, no two disks were alike. Writing data to the original wasn't a big deal - once you knew where the bad sectors were, skip over them.
Is it breakable? Of course. Would the average person be able to? Of course not.
People who create works have the right to decide, within the limitations of the law, how they are used. That includes how they are sold, licensed, or whatever. Without that incentive, most of the stuff you experience (books, music, movies and tv shows, professional sports broadcasts, most radio and tv stations - wouldn't exist. TV wouldn't exist as we know it today because there wouldn't be much worth watching on it - same as almost all the stuff on youtube is crap. Most of the decent games are possible because copyright makes it financially viable to develop them. You might not like patented medicines, but without those patents, and the chance to make money off of drugs, the research won't get done and they won't get put through the testing and production phases.
As just one recent example, look at the self-driving car craze. Without a financial profit motive, nobody would be developing one. That financial profit is made possible because you can recoup the money invested via sales, without having to compete with someone who didn't have to spend to develop one, just ripped of your design and sold it for less (because they can afford to without the sunk costs you incurred).