That's why Russel's teapot hasn't been falsified. We've barely managed to produce any evidence against it. Therefore, if you want to explain an observed phenomenon, it's perfectly valid to explain it in terms of Russel's teapot.

Though I think you could have picked a better analogy (specifically, one that makes significant predictions about the future), I agree with what you're saying. Let me say what I should have said:

The thing is, quantum mechanics looks like the Copenhagen interpretation. The Copenhagen interpretation and the many-worlds interpretation are practically identical in the predictions they make. Therefore, if you want to explain an observed phenomenon, it's perfectly valid to explain it in terms of wavefunction collapse.