what Bell did is another experiment involving the correlation of different polarization of the lights at different angle. It is very difficult to see the direct relation of his experiment and the above mentioned fundamental differences in hidden variable theory and copenhagen interpretation. Again here politics takes over, complex formulas and experiments seems to be able to shut most of the people's mouth
It's not just theory; there is now hard evidence, too. Here is photographic proof, the first ever image of quantum entanglement (and violation of the Bell inequality), from the University of Glasgow last July.
paper: https://advances.sciencemag.org/content/5/7/eaaw2563
the experiment:

The experiment just proves what the experimenter claims, nothing more. This is what I call technology politics, very common in modern physics. Need a better way to convince other people
That's exactly what I see in the laboratory that my friend professor was doing all day, lots of lens and filter and electronic devices, but he still can not make a quantum miner
I have promissed to him that he will make billion dollars by inventing a quantum miner, he only need to work out the theories, I do the physical production, but he obviously have no idea how to even form the concept