Email is OK as a communication tool. But companies use it as a task/to-do list and to work together on tasks. Email is terrible to achieve this. You will end up with lots of emails and multiple versions of the same documents... That is why I wish someone fix email! :)
Tools like Basecamp and Trello do a good job with project management, but they aren't a 100% substitute for all the various functions of email. I sometimes think that a hybrid between email and a forum/bulletin board would be the best way to manage complex communication, instead of convoluted cc lists...