What a wild claim. You can't just say it's arguable, you have to actually argue it. Personally I think it's true but only in a metaphorical way that doesn't apply to hallucinogenic drugs; inasmuch as it applies to hallucinogenic drugs, it's false.
It's a interesting train of thought if nothing else. How would we "prove" a thing like "humanity benefits from being able to create, share and read books?" for example? Or that we can organize in grassroot movements? It's also really hard to qualify directly, as the impact is so indirect.
Same with psychedelics, a lot of scientists, researchers, creatives or even business-people attribute psychedelic usage to some of their success in their fields, but how can we really know if it was because of that or not?
If you do want to get into the "where big":
Shamanic/ritual/religious/social practices that wholly involve hallucinatory experiences (both with and without the aid of hallucinogenic substances) are well attested and documented throughout human development.
So the existence is there; if you want to argue that actually it was a Bad Thing for human collectives, from Siberia to the Amazon, from 50k years ago to the present day, to engage in these practices and that they'd have been much better off Not Doing It, I guess the burden of that proof is on you?
It is one of my favourite quotes. However, i think it only holds amongst intellects of his calibre.
I've come to the position that false beliefs aren't necessarily harmful, in the context of proles who already believe a lot of wrong things.
I mean, people claim therapeutic benefits to psychedelics, and there is some evidence.
Your analogy is exactly backwards.
How is that different from psychedelics? We can "see" their physical counterparts (and chemical reactions) in people's head and body as they trip too.