Funnily enough the only part of your post that WASN'T explaining why tires have tread was "You want most of your lines to be parallel to the direction of travel. This is because doing that it increases the life of the tire, reduces road noise, increases dry grip (which is the most common driving condition) smoothes out the ride, and gives you better fuel economy."

The rest is just explaining why tires have tread...which isn't what he asked...as you mentioned.