My view is that the departure from reality started in the 1920s with the introduction of the multi-dimensional wave function as solution to a linear scalar Schrödinger equation, with 3N space dimensions for an atom with N electrons. Such a wave function does not describe real physics, since reality has only 3 space dimensions and the only way out insisting on the truth of the linear Schrödinger equation as given by God, was to give the wave function a statistical interpretation. But that meant a non-physical and non-real interpretation, since there is no reason to believe that real physics can operate like an insurance company filled with experts doing statistics, in Einstein's words expressed as "God does not play dice". The statistical interpretation was so disgusting to Schrödinger that he gave up further exploration of the quantum mechanics he had invented.
Schrödinger believed that the wave function had a physical meaning as a description of the electron distribution around a positive kernel of an atom. A non-linear variant of the Schrödinger equation in the form of a system of N equations in 3 space dimensions for an N-electron atom was early on suggested by Hartree as a method to compute approximate solutions of the multi-dimensional Schrödinger, an equation which cannot be solved, and the corresponding wave function can be given a physical meaning as required by Schrödinger. I have explored this idea a little bit in the form of Many-Minds Quantum Mechanics (MMQM) as an analog of Many-Minds Relativity.
MMQM seems to deliver a ground state of Helium corresponding to the observed minimal energy E = - 2.904, with the 2 electrons of Helium distributed basically as two half-spherical shells (blue and green patches) filling a full shell around the kernel (red) as illustrated in the left picture. This configuration is to be compared with the spherically symmetric distributions of Parahelium in the middle with E = -2.75 and Ortohelium to the right with even larger energy to the right:
QM with PEP thus does not describe even Helium correctly, a fact which is hidden in text books, while the non-spherical distribution of MMQM appears to give the correct energy.
MMQM does not require any PEP and suggests a different explanation of the electronic shell structure of an atom with the numbers of 2, 8, 8, 18, 18... of electrons in each shell arising as 2 x n x n, with n=1, 2, 2, 3, 3, and the factor 2 reflecting the structure of the innermost shell as that of Helium, and n x n the two-dimensional aspect of a shell.
The Farewell to Reality from modern physics was thus initiated with the introduction of the multi-dimensional wave function of the linear Schrödinger equation of QM in the 1920s, and the distance to Reality has only increased since then. Once the connection the Reality is given up there is no limit to how far you can go with your favorite theory.
QM is cut in stone as the linear multidimensional Schrödinger equation with wave function solution being either symmetric or antisymmetric and satisfying PEP, but QM in this form lacks real physical interpretation.
The exploration of non-linear Schrödinger equations in 3 space dimensions with obvious possibilities of physical interpretation, has been pursued only as a way to compute approximate solutions to the multi-dimensional linear Schrödinger equation, but may merit attention also as true models of physical reality.