The best description that I have heard that most users that I have spoke to agree on is that psychedelics have an aspect of "flattening" emotional significance of things by making any thought that you have just as "prominent" as another experience. The reduction of blood flow to the area of the brain that is responsible for parsing reality means that your thoughts become more prominent, making any thought of change or improvement just as impactful mentally as what you believe your reality is.

This in turn gives lasting perspectives in the form of "hey, I am able to think and feel about things differently and not locked into this pattern of thought", which could be the necessary catalyst for change.