I've done a lot of tripping, and I've come to this same hypothesis independently. I believe this explains a great deal about the visual geometric and fractal patterns you can see on psychedelics and also that analogous things happen within the auditory processing system, memory, emotions, and so on when you trip.
So much of tripping comes down to turning up the gain on signalling in your brain, which causes feedback pathways to start resonating. This results in colour saturation, tracers, geometry, exaggerated patterns and edge detection, echoing, reverbs, increased impact of thoughts, and following thoughts down deep rabbit holes etc.
None of this is to reduce the experience, I love psychedelics and think they are super important. But that's whole other discussion.
i have the sense that one could construct a whole "ancient aliens" style ideology and paranormal theory of history around hallucinogens, but it would just be entertaining junk.
I've said before that I think the geometric patterns in hallucinations resemble analog signal feedback, inside an analog signalling system (your brain) that has been impaired by a chemical. other dimensions and beings aren't necessary to the explanation. there are theraputic uses for breaking cycles of thought, but I'd argue a non-spiritual view of drugs based on signalling feedback and channel impairment is sufficient to describe their effects.