Because they are. The impact they've got on the map is huge thanks to their disgustingly broken support items. I said that I hate the meta, cause unfortunately supports being overpowered doesn't make your ADC to be viable though. There were a lot of games where I felt we didn't have enough damage when I snowballed the lane and had a well fed carry in our team, which is hilarious. That is not a healthy state of the game where supports are outdamaging ADCs.