The thing is, though, that almost invariably several competing hypotheses are tested at the same time. So the one that emerges is the "best fit", which in turn means that the other ideas weren't. While a better theory may -- and hopefully will! -- come along later, it's rare that the theories currently adopted are discarded entirely. They have, after all, passed the required tests, and are therefore right. Or at least, right as far as they go.
Curiously your own link you provided earlier demonstrates this idea. Classical Mechanics passed the scrutiny of over three centuries and remains core to our understanding of the world. It's just that Relativity is better at higher speeds or with stronger gravity, while Quantum Mechanics is the theory we need for atomic scales. And yet, we still use the old theory. Because it works! It just doesn't work all the time. But it's not been thrown aside as useless.
Our scientific understanding changes, evolves, and improves. That change to fit the available data is its great strength.