I agree, large companies like Elsevier generally do not care about low magnitude piracy, but something like SciHub is probably to them an existential threat, and something they would throw everything at.

The music industry saw a revival of sorts, with Spotify and other streaming services offering a reasonably priced and extremely convenient alternative to piracy. That sort of an arrangement, while still not ideal, is probably the best Elsevier can hope for in the long term - provided they can offer a sufficiently interesting alternative to scihub.