I have used and read Tarot for people and have studied Tarot. It does work if the person being read for wants it to work. The question you have to ask yourself is, why does it work, and who is answering your questions? Do you want those questions to be answered? Were they meant to be answered? Asking questions to the Tarot is like putting the cart before the horse, really, isn't it? I mean, you are asking these cards to tell you the motives and inner thoughts of others, what will happen in the future and so on...some people even want to know about their health. But doesn't that take away all of your own power over your own life and give it to some unknown entity? Is that entity good, or evil? Does it have your best interests at heart? There is a lot to think about when considering leaving major life decisions to the Tarot, the Ouija board, anything like that. I've come to believe anything works if you believe in it and empower it and if it's delivered to you by a skilled practicioner. But I also do believe there are many powers from many sources that can work for or against you. You have to decide whether to tap into negative or positive powers, and choose the sources of those powers, carefully. I would say only this as advice: the future is not written in stone, and each thing you do changes every future thing you do, which is why in all of those science fiction movies you can never interfere with time: things are changed by the smallest detail being moved, changed or interfered with in any way, so fate is not fixed, it's completely malleable. So how could a Tarot card say "this will happen" and that be a finite, definitive fait accompli?
We need to be freer with our minds and more trusting of our instincts, therein lies our path and our compass to direct us to our future.