An interesting stance to take and here I'll make the sad confession that I don't agree.
But given the novelty of your perspective, is there anything that you could say about why, in your humble opinion, our brain even has DMT receptors? I'm highly curious about this. I accept that you're probably not a neuroscientist and I hope I'm not putting you into a position where you feel the need to defend your otherwise lovely views.
You're more than welcome to disagree, I'm aware that my views are not common. I'm also perfectly willing to discuss my views with you on these topics at length although I'll warn you that doing so in full would not be quick or simple. (And I'll probably talk too much about myself.)
I am indeed not a neuroscientist, just someone who's experienced a lot of things with and without drugs and familiarized myself with many different communities related to it. I have done a lot of amateur research into the science about these things though too, and consider myself to know significantly more about drug science than the average drug user. I'm willing to answer your question, but I have to ask for clarification, what specifically are you referring to with the term "DMT receptors"?
DMT is a pharmacologically complex molecule, binding to a wide array of receptors such as for serotonin, norepinephrine, dopamine, and histamine, as well as sites like trace amine-associated receptors and sigma receptors. If you're referring to one specifically, I would guess it's maybe the sigma-1 receptor? This receptor is often the one singled out for trying to decipher why DMT itself exists in trace amounts in mammal brains, but it's actually not exclusively a DMT receptor, also binding other trace amines as well as neurosteroids including even testosterone and progesterone; furthermore, it's highly questionable whether this receptor site has any relevance to what people consider to be the more distinctive recreational subjective effects of DMT, and I'd personally have to say I haven't seen much evidence of it being important in that way. Most likely, based on the evidence I've seen, DMT produces its primary effects through 5-HT2A receptors, like other psychedelics, and at least some of its distinctiveness probably just comes from the fact that it does stimulate many other receptors as well at the same time, potentially making the experience more cognitively complex than something like a more selective 5-HT2A receptor agonist would do.
However, none of these actions are specific to DMT, far from it. Even despite DMT being present in the brain, every receptor known to be activated by DMT is, to my knowledge, simultaneously known to be activated by other brain chemicals as well which have at least as much evidence behind their relevance to human life as DMT if not significantly more so. So, based on my current knowledge, I personally would not say that there are "DMT receptors" in the brain. It seems very likely to me that the recreational subjective effects of DMT largely derive from it mimicking other brain monoamines such as serotonin, like other psychedelics.
Again though, DMT itself is in the brain, and I'm not saying it definitely has no purpose, or even likely doesn't. That being said, that alone doesn't mean anything clear or suggest relevance to the subjective effects of DMT. Bufotenine (5-HO-DMT), 5-MeO-DMT, morphine, codeine, ethanol, GHB, and nitrous oxide are all found naturally in mammal brains too.
While I would also like to understand the brain on this level, I'm not personally sure it really matters to understanding the effects of DMT in the way that we're discussing here at least, but that's because I think the way we experience DMT when using it recreationally is more likely resulting from an alteration of "normal" brain activities as opposed to triggering some process naturally meant for DMT, although I have encountered people who hold the latter view before too.
