Why does it matter though?

I'd wager few people would use Google to search content on Sci-Hub. The normal usage is simply entering the DOI of the paper you want on Sci-Hub's front page.

Note: you can still search for Sci-Hub itself on Google, and find plenty of pages listing active mirrors.

They could censor that in Chrome as well, in multiple ways. That's one reason why having your DNS services provider, browser provider and search provider as the same entity is an extra risk.