You could make the argument that shackling is like safety gear so that the NHP in this strange lower dimension doesn't fuck up the local wildlife or planets.
it's like, interestingly symmetrical the shackled and unshackled versions of an NHP are essentially 2 different people, neither of which typically wants to be replaced with the other
side note, particularly after what Catherine said about rewriting thoughts, Rebecca is starting to theorize that what the Anglerfish does to humans might be something like its version of shackling NHPs
take an incomprehensible extradimensional alien entity and force it into a version that's able and willing to interact with you in terms you can understand
the shackled and unshackled versions of an NHP are essentially 2 different people, neither of which typically wants to be replaced with the other