There is a theory that the connection between the right and left hemisphere of the human brain has been diminishing over generations (The ancients used to audibly hear the voice of the gods, which was likely the right hemisphere, but that ability diminished around 4-5000 years ago). I wonder if all these psychadelic drugs are doing is enhancing the communication between right and left, or perhaps suppressing the left…
Let me put forward a metaphor: you're currently experiencing reality indirectly, through an imperfect lens which throws into focus an internally coherent system of perceptions we might colloquially call a "seratonin hallucination". You could think of the changes that occur after taking e.g. LSD as replacing that lens with another one.
Is it a less accurate one? Almost certainly it's one less valuable in helping our ancestors adapt to the evolutionary pressures they faced than our normal neurochemistry; in terms of representing an "objective" reality though, there may be some ways in which it affords a more faithful depiction.
Or perhaps not; it's hard to say. I think the value lies not in the affordance of new and more authentic powers of perception, but in shaking up the assumptions we make about how objectively truthful our "normal" experiences might be.