News flash: It's humanity, not any particular generation. When a generation comes of age, they sit up and go whoa! Look at all the problems here! There's NO WAY we'll make the same mistakes! F**K YOU, generation in power! But, any generation gets old enough, their need to make a living will begin to trump their idealism. The average members of the group make compromises little by little, year after year: WHOA, gotta win the cute guy/pretty girl, WOW kids take a lot of energy to raise, DAMN, I need that promotion, and their integrity slowly withers from a million tiny nicks and cuts over the decades. Eventually, there's one last real activist left, surrounded by a room full of lip service. But here's the kicker: Once a majority of them have been turned into bitter husks by time and life, some of those average husks will possess the levers of power. They'll have seniority. They'll be in charge of placing the ad on indeed.com. They'll have been elected enough times to be the top dog on their committee.
So eventually, in another 30ish or so years, the Millennials will have those levers. At which point, they too will probably cause plenty of wars, economic strife, exacerbation of new and different environmental problems, hoarding of wealth, 3rd world exploitation, and generally do bad stuff until Gen Alpha comes of age, notices these problems, and says OK, Milliennial! WE didn't start this! LOOK at all these problems! It's all YOUR fault! At which the millennials will retort, "get a job, you shiftless alphas! You know nothing of life!" At which point the cycle repeats.
Prove me wrong, folks. (And I really do mean it, please, for the love of humanity, preferably before 2049, BY YOUR ACTIONS, save the species and prove me wrong.)