Ok, how? Before the days where we began to preserve media in physical form, all the music and stories we knew were all spread by word of mouth. Obviously this meant that many populations were segmented over what ideas they were exposed to, but they were all free to regurgitate all the songs and hero stories of their times. People themselves would put their own twists to this form of media and so long as it wasn't at the expense of a powerful person, they could do whatever the heck they wanted.
Copyright law requires that NOBODY partake in the regurgitation or personal evolution of an idea. Yes, people still sing the current tunes of the day... But if it gets caught on camera, their accounts can get suspended. If someone wishes to create their own story within a pre-existing fantasy or to retell said stories, they will be shot down with C&D letters. We have all been told how outrageous it is that living necessities are constantly being commodified, but all of this started the moment we allowed the few to control the media by barring participation on the legal ground.
If we wish to have unrestricted free speech, this is where we have to start to negotiate for the sake of our memetic nature.
Copyright law in some medium, when it isn't mind numbingly complex, can help some artists, we'll take writers in this example. In the literary world, copyright may help prevent against leechlike mimics who will just change your work a little here and there from profiting off of shitty 'spin offs', and could thus also make a bad name for the original work of art or degrade its reputation. A more concrete example could be people trying to
sell fanfics of whatever popular literary franchise you can think. Not actually writing one and just sharing with a community, that's where the vast difference is - aside, fanfic is an awful way to write and is just a little step above outright plagiarizing, but that's just my opinion.
Copyright in some instances can help little artist too, but of course the lion's share goes towards the Lords of their field. One instance of copyright helping the little guys in which, Avatar (the James Cameron one), the court ruled, 'stole' the idea of floating islands from a fiction author, and thus recompensed the author for this.
But thankfully public domain exists which is a reasonable trade off for copyright, for instance look at all the vampire and werewolf fiction available, that concept of vampire and werewolf is public domain. Same thing with Greek myths (American Gods, Percy Jackson etc etc). Frankly enough, there are treasure troves of obscure and esoteric public domain stories and ideas which I'm sure if you do some digging can yield extremely original stories. Take for instance African folklore, mix that with some aboriginal myths, and you've got something (maybe) original?
But legality aside, when looked from a philosophical stance, can someone possibly own an idea? I can't answer that. But, when you have an idea and it's not heard, and some sly guy steals your idea without acknowledging you and claiming it's his own, wouldn't you be upset? Copyright in theory, was supposed to stall this drama we've all encountered to a degree (someone taking our idea and getting rewarded - pat on the back etc) from proliferating out of control in our avarice society.
Free speech is also a tricky subject, because when you are using a platform on the internet, remember when you create an account and you have to click on the small tome of I agree to the conditions which we never read? That means that's a contract you just 'signed' with a private company, and all those rights go bye bye, and the owners can do whatever they please and not get punished legally for it if one cries foul. Free speech
usually applies in person to person interactions, like you can go gather your friends and animals and march into a plaza and demand purple colored hamburgers with sprinkles, and nobody can censor you for that, even if they like green colored hamburgers with orange icing, but hate speech is not free speech. Hate speech is not only disgusting, it can also be penalized. Beware of the cancel culture and free speech too, there's an aura of would be censorship going on there, but that's a completely different topic.
All this can bridge into an infinity of other discussions, and I'm no expert in this matter.