[durrrrrrrrrr]

It's not an anti-tracking thing.

It's so you can't log in and read stuff, or get sucked down a distracting click-hole of videos, jokes, chit-chat and bullshit. It breaks the reflexive bookmarks, links from other sources and general habitual url visiting.

[Kluny]

No, I mean literally, if I paste those strings into my etc/hosts it won't block any of those sites. It simply doesn't work. You can still load the sites. It takes stronger measures to block them. I have to edit my hosts file all the time for work anyway, so I ended up installing SelfControl and I turn it on when I feel like I need it.