It could make somethings faster, not everything, but so far the number of useful somethings that people have come up with is very small. A quantum computer is

It could make somethings faster, not everything, but so far the number of useful somethings that people have come up with is very small. A quantum computer is not a general purpose computer than can be programmed in the way we're used to - it's more like an analog computer that is configured rather than programmed. It's only useful if the problem you are trying to solve can be mapped into a configuration of the computer.