Scihub is completely different from Libgen in terms of ethics. No academic has ever written a manuscript for publication in a peer-reviewed journal because they were going to get paid for it. There is nothing whatsoever ethically problematic in accessing Elsevier's content on Scihub. Those journal articles should be free to the world, not least because the reasearch is often paid for by public funds.
Do not confuse what I'm saying. I am not saying that I think Libgen is a bad thing. I am saying it is a difficult area from a moral/ethical/economic point of view. Scihub and Libgen are the most fantastic libraries the world has ever known. Literally. It seems pretty clear that making them available to someone in rural Angola is a good thing to do. I work in a highly developed country and it's slightly less clear that the anarchy should extend to benefit me, but honestly I'm happy that it does.
Just to add my 0.02$ as a soon-to-be-phd-dropout, I once downloaded my own paper from SciHub after I lost the stupid PDF and of course the publisher wouldn't let me get it for free. If anyone plans to assemble a torch and pitchfork mob, by all means let me know.