Sci-Hub distributes information that paid journals have already done the work to curate. Once paid journals go away, Sci-Hub will end up like GitHub: a million random repositories maintained by random people with no index. Only there's a whole host of new problems that scientific research needs to solve that is more complicated than some poorly written lines of code. The stakes are different; the errors lead to worse outcomes, rigor is much more important, and finding relevant information in the vast array of available research is much more important.
I'm not saying publishing today is great. It very much isn't. But throwing the baby out with the bathwater isn't a better solution. It's like saying, this government is corrupt, let's throw out the government! Look how well that works for countries that don't have a new government prepared to replace the old one.