I hate copyright too, and I agree you shouldn't own ideas, but the library of babel is a pretty weak refutation of it.

It's an algorithm that can generate all possible text, then search for where that text would appear, then show you that location. So you say that text existed long before they typed it, but was it ever accessed? The answer is no on a level of certainty beyond the strongest cryptography. That string has never been accessed, and thus never generated until you searched for it, so in a sense it never did exist before now.

The library of babel doesn't contain meaningful information because you have to independently think of the string you want it to generate before it will generate it for you. It must be curated, and all creation is ultimately the product of curation. What you have there is an extremely inefficient method of string storage and retrieval. It is no more capable of giving you meaningful output than a blank text file.

A better argument against copyright is just that it mostly gets used by large companies to hoard IP and keep most of the rewards and pay actual artists almost nothing. If the idea is to ensure art gets created and artists get paid, it has failed, because artists get shafted and the industry makes homogeneous, market driven slop, and Disney is monopolising all of it. Copyright is the mechanism by which that happened.