> and need to use them/cite them will be forced to purchase them regardless

Not at all, but, they will review a lot more of them before deciding which ones to cite if sci-hub is available. BTW arxiv is for physics math and cs, while the closed access problem is mainly affecting life sciences which don't use arxiv, and are only partially using biorxiv / medrxiv. There's still a very archaic culture there, mainly because there's no other easy way to ascertain some scientists' value.