It's not really useful to me when someone tells me that they know what will and won't work for my life, the people around me, my community, and so on.
That tends to scale up pretty far: it's not really useful to me when someone tells me what will and won't work for the entire population of planet Earth. There's biology and educated guessing and mathematics, and then there's fortune telling and speculation. I think one of the great wonders of life on this planet is that none of us can know, none of us can grasp the seemingly infinite variables that contribute to what happens from this moment forward.
I don't think we should be blind to data and trends and evidence and probable outcomes, and that we should not incorporate our observations about the world into our decision making. But, I also don't think the human brain was designed to cogitate on the lives and futures of the other 6.5 billion people on the earth, or the other millions of square miles that we don't inhabit. It's a fun exercise and a worthwhile one, but it perplexes me when people insist that they can discern the right way for all of us to live based on what might or might not come out of the billions of interactions happening every second. The magic of the universe seems well beyond the grasp of any one person.