The only claims QM make is about probabilities of measurements, and you can verify these experimentally, as we did, repeatedly. You are free to interpret these as many universes, pilot waves, or fairies playing tricks on scientists, suit yourself.

But we know for sure if it's fairies (or any other hidden variables) - they have to conspire globally. Cause otherways the experimental results couldn't happen the way they did cause fairies in place X wouldn't know which way to nudge the results to be consistent with the way fairies in place Y nudged them.