[equivrel]

The objects in boxes scenario you have described is useful to think about when coming to grips with QM and entanglement. However, one needs to be careful, because there is an additional subtlety: QM can have measurement scenarios that are not only entangled, but also non-local [1]. This means that it is provably impossible to endow the variables that you are measuring with prior, local assignments, e.g. like in the boxes scenario. So there is actually another phenomenon present in QM that makes it weird, and is strictly speaking distinct from entanglement.

[1] - https://en.wikipedia.org/wiki/Quantum_nonlocality

[platz]

locality is looking suspect for other reasons too, as it's one of the only ways to avoid 'black hole firewalls' [1] (the other way to avoid firewalls involves giving up conservation of information which would be bad for QM theory).

[1] Black hole Firewalls with Sean Carroll and Jennifer Ouellette https://www.youtube.com/watch?v=_8bhtEgB8Mo&t=3634s