Many Worlds is crackpot pseudoscience. The arguments presented in this article are incoherent.

(1) It starts by criticizing the measurement postulate, but Many Worlds does not get rid of the measurement postulate. In order to divide the wavefunction meaningfully up into branches, you have to choose a basis to represent it on, and nothing within the wavefunction tells you which basis to represent it on. Everettians always talk about it as if the basis you should represent it on is the basis you are making the measurement upon, which then allows you to interpret, for example, that there exists branches where copies of yourself see different outcomes according to the Born probabilities. But this is just the measurement postulate by other means, because the choice of basis depends upon the choice of measurement.

(2) Many Worlds does not solve this problem, because it does not get rid of the measurement process to begin with. When confronted with this fact, many Everettians will admit how they describe the branching is not quite accurate, and that branching doesn't even really exist, because there is no objective way to decide which basis to represent it upon, so any choice of branching structure is subjective. However, once Everettians admit to this, then their "theory" stops being able to make a single empirical prediction at all, because the singular outcomes we perceive are taken to be an illusion caused by a branching universe, but the branching is also taken to be an illusion without any objective reality, and so there is an illusion grounded in an illusion without any physical origin. Since nothing connects the wavefunction to what we perceive, it cannot make any empirical predictions at all.

(3) The third part of the particle entertains the same nonsense that Everettians engage in themselves, which is to suggest that if quantum effects can be scaled up to macroscopic scales, that somehow provides evidence for Many Worlds. What the article leaves out is that Many Worlds does not predict quantum effects at any scale, because it does not make any empirical predictions at all. It also leaves out the fact that nothing about scaling up quantum mechanics proves Many Worlds is correct, because this already presupposes that Many Worlds is correct for macroscopic objects, which they have never established.

(4) Decoherence does not do jack shit for Many Worlds because it cannot be meaningfully even defined within its framework. For decoherence to work, you have to already presuppose a meaningful distinction between a system+classical environment. You can always describe the system+environment together as a combined wavefunction, and the distinction disappears. There are is no objective criterion within the wavefunction itself for making this separation. It always has to be presupposed based upon the measurement setup, and this is just the measurement postulate by other means.