Wort chillers are more necessary when you do full boils like a lot of us do which means you can't add cold top off water so you have to get 5,6 or 11 gallons of beer in the kettle down to 65-70F as quickly as possible. It could take hours to get that much wort chilled using an ice water bath.
That's pretty much it. For extract kits using partial boils with top off water there is no need for a wort chiller.
Next up: Red Zombie IPA
Primary #1 + 2: Centennial Blonde Summer Ale
Bottle Conditioning: Shmuck's Belgian Dubbel, Dry Irish Stout
Drinking: Citra-tennial APA, Honeybee American Wheat Ale