I've always been confused by the claims of quantum computing, I'm hoping one of the clever folk here can steer me to an understanding. Doesn't the very nature

I've always been confused by the claims of quantum computing, I'm hoping one of the clever folk here can steer me to an understanding. Doesn't the very nature of superposition and uncertainty make determining when the process has solved the problem impossible to determine? Its like, when you look at the data, you change it, and if it wasn't solved, you've already forced it into a state, and if it was solved, by observing it you may change it to something else. How are these problems solved with quantum computing?