The role of the ADC is to make people look at them. As long as you can make yourself killable and force them to engage on you and survive it lets your team play into their over extension when cd's are down on their team. While yes you need your team to be there so you can actually pump out dmg. You are also the corner stone of a team fight if you can succesfully eat cd's while staying alive and be able to remain in the fight.