The human mind is clearly wired to be able to experience spiritual and mystical states, and something within us seeks that (or most people at least). Psychedelics are great tools for accessing these kinds of states, and it's true that you won't be able to "trip" unless you take a psychedelic, but there are many ways to experience profound mystical/spiritual states without tripping. They can happen spontaneously, and they can happen when someone seeks them with purpose.
I think that by and large our society today does not value these things very much, but historically humans have been much more in tune with the mystical/spiritual, especially the closer you get to the root of human culture. I'm not sure whether I would have broken through social conditioning to experience the mystical and spiritual without the help of psychedelics, but it's not because it's not possible for me to do so without them, it's because my learned belief system simply did not account for these things and I was unlikely to find them without something to break me out of that forcibly.