Champions

[Kaden]

Sivir's W makes her one of the highest-dps champions in team fights. It gives her almost unrivaled pushing power, too.

Against bots you won't notice it too much, no, but it is a very useful skill. Most CC effects are attached to pretty slow/obvious particle effects, making it useful for preventing that Taric stun or that Ashe arrow. If you play enough, you'll just get a feel for when someone is going to try and CC you (there's a reason most Annies flash+stun: it's pretty damn obvious when it's coming) and you'll find the Spell Shield that much more useful.

Bloodthirster is a really good item on Sivir, since she can kill minions really fast to get all that bonus Attack Damage and Lifesteal. Some people also get Warmog's Armor for the same reason, but I don't recommend starting with that. Her Q only scales off of bonus Attack Damage, so it's really helpful to get some damage before building defense.

Because of her shield, her passive, and her ultimate, Sivir can also afford to itemize for raw AD moreso than other ranged champions.