Earlier quoted context omitted.
Blocking Google Analytics is the main point of any blocker I would consider using.
Many sites rely on Google Analytics to be able to do their own promotions and sponsorships, which is the only way they make money other than ads. By blocking GA, the site doesn't see you as a visitor. So, you use the site resources, don't see ads and don't add to their user/page view numbers. Plus, there's the fact that lots of sites use GA to handle inter-page click tracking so they can see what paths users take to…
What? How does that even work? If GA goes down, their site just stops working until it's back up?