The interpretations of what the math is saying happens a varied and sometimes contradictory.
We can predict what's going to happen extremely well, we just can't tell the story of what's happening. And there's been a century of trying to avoid the weirdness and failing. The problem might just be our brains evolved in a world that behaves so much differently that we can't understand.
Yes but also absolutely not. The evolution of the wavefunction when nobody is looking is unitary, which among other things means it is time-reversible. That math works extremely well and predicts the correct outcome.
When we are measuring a quantum system, the probability distribution of the measurement outcome is described by the Born rule, the amplitude of the wavefunction squared, and the collapse postulate tells us that after the measurement the wave function will be in the measured state, which is a non-unitary and non-time-reversible process. That math works extremely well and predicts the correct outcome.
But - really big but - what is a measurement device but a huge quantum system, what is a measurement but a quantum system and a measurement device and an environment undergoing time evolution? So both descriptions should apply, unitary time evolution and wave function collapse, but that can not be the case because they are incompatible, one is unitary, the other is not. The mathematical description is inconsistent.
I often observe that humans are wired to create causal stories, whether we intend to or not, even in circumstances, we know are false.
A great example involves flipping a coin. Even people who know it's basically an independent 50/50 chance every time get drawn into thinking about "hot streaks" and "overdue for the opposite."
It's arguably a superpower that has given us lots of agriculture and tools and technology and culture, but like hunger and obesity we can't just turn it off when it gets maladaptive.
Humans are very good at pattern matching and explanation and that's what's given us success, but false-positive matches sometimes are the result and need to be corrected down a bit
The mathematics of QM works extremely well.
The interpretations of what the math is saying happens a varied and sometimes contradictory.
We can predict what's going to happen extremely well, we just can't tell the story of what's happening. And there's been a century of trying to avoid the weirdness and failing. The problem might just be our brains evolved in a world that behaves so much differently that we can't understand.