Hm. When you say that QM breaks reality, are you saying that independent reality with definite properties does not exist, when not being being observed? Isn’t that rather solipsistic?
I didn't say it breaks reality. It breaks *realism*: the idea that things have definite properties at all times and that those properties determine what happens.
Superpositonal states are good examples of not having definite properties: light might not be either right or left circularly polarized, but rather a combination of the two. Electrons might not have spin up nor spin down, but a combination of the two.
Entanglement is another aspect of this same phenomenon. For example, suppose we have two entangled electrons. One is spin up and the other is spin down, but which is which? The answer is that this is not definite: it is probabilistic: if you measure one and get spin up, the other will be measured to have spin down. But prior to the measurement, there is not a definite answer to which is spin up and which is spin down.
That is the aspect of QM that Einstein didn't like. But it is precisely the aspect that has been shown to be the case time and time again. Objects do NOT have definite properties between interactions with other objects: they have probabilities for having different values for the properties. THAT is the most unusual aspect of QM.
Also, when you say that most physicists are okay with it now, don’t you mean most theoretical physicists - in other words, mathematicians - are okay with it? No one can possibly deny the success of QM in developing new technologies, that’s not in question. Thus Feynman’s ironic injunction to “Shut up and calculate”, became an effective manifesto - but an unsatisfactory one, nonetheless.
Theoretical physics is not the same as applied mathematics.
but here's the question: why is 'shut up and calculate' unsatisfactory? partly because it doesn't address what philosophers say we should be addressing. But maybe the philosophers are wrong about this? At some level, for a fundamental theory, there can be no deeper explanation: it *has* to be that we 'shut up and calculate'.
Now, I *do* think there are interesting philosophical questions. but to answer them, we need to get away from our ideas about 'things having definite properties at all times' and away from the notion that causality is fundamental. QM is NOT a causal theory! It is a probabilistic theory. As such, it simply not compatible with classical philosophy.
What QM cannot currently give us - and neither of course, can classical theories of which relativity is one - is a complete description of the universe we live in. Something Stephen Hawking, echoing Einstein’s sentiments, declared to be the ultimate goal of all physics.
I do agree with your observation about holding onto realism btw. We need to be willing to let go of old ideas when they no longer serve, of course.
Finally, when you say that QM breaks realism but not locality, isn’t this in a sense an application of the uncertainty principle - in other words, validating one property is impossible without partially invalidating the other? That’s just a thought, really.
In a certain sense, the uncertainty principle is behind superpositions and entanglement. It really is the basic philosophical notion that needs to be adopted, thereby rejecting classical understandings.