The benefits of meditation are well-substantiated, although not as well-publicized as they would be if this was a drug. If someone came up with a drug that has as many benefits with as few side-effects, you can bet everyone would have heard about it by now. Why? Because you can patent a drug and have a monopoly on it and profit by it. But as it is, anyone can teach meditation, anyone can learn it, and any promotion money you spend on telling people the benefits of meditation would help your competitors as well as yourself.
In other words, just because something is well-known doesn't make it good. And just because something isn't well known doesn't mean it's not the best thing going.