First of all, most teenagers don't have access to tvs, let alone anime. This is due to that most of the world's population lives in impoverished (po) areas without access to modern commodities.
As for those who do have access to anime, most teenagers have tougher lives than previous generations, having to learn more, and having more expected of them. Also, have you seen the news lately? Most of what they show is death, destruction, and overall the problems of the local area, region, and world. Hardly any news agency will show much good news due to that bad news sell better than good. Teenagers use anime as a recently growing yet almost unkown philosophy- escapism. Basically, escapism is using anything, whether it be anime, self abuse, reading, sleep, even shopping, to escape from real life and the problems found therein.