The problem is that we need a convincing mechanism to explain how the irreversibility implied by the Copenhagen interpretation arises, which to my knowledge no

The problem is that we need a convincing mechanism to explain how the irreversibility implied by the Copenhagen interpretation arises, which to my knowledge no one has come up with yet. What we understand so far is: * the measurement process can be described as an entanglement of a quantum system with a large external system, followed by a dephasing of the wave function that is caused by the huge number of degrees of freedom in the external system. * this dephasing decouples the individual terms of the wave function of the system that is being measured, thereby effectively suppressing any further quantum effects in those measured states. This is what we call a transition from a quantum state to a "classical" state. * the measurement process itself is not a discrete event: We can perform continuous weak measurements on a system's state, which will only partially collapse the wave function (there have been many experiments done on this e.g. by Serge Haroche's group and more recently with superconducting systems as well). * this whole process is completely reversible and can be described by the Schrödinger equation. Now, if we want to introduce irreversibility into this picture (which is required for the Copenhagen interpretation), we need a mechanism for it to arise. To my knowledge, no one has come up with a good theory for this, as it would require to modify the Schrödinger equation in a way that subtly depends on the characteristics of the system being measured and the measurement system. This mechanism would need to contain a variable A that would account for the size of the measurement system, as we need to preserve reversibility when the measurement system is small (i.e. has a small number of degrees of freedom), while destroying it when the measurement system is macroscopic. I'm honestly a bit surprised that no one makes this argument in favor of the many-worlds interpretation of quantum mechanics, as it's the only theory which accounts for all experimental evidence while not forcing us to invent a mechanism that "eliminates" the many realities that we don't want to accept, while in fact they arise naturally out of the theory. I think that many people just don't want to accept that the universe could work this way, even if it's the simplest and most straightforward explanation.