It really depends on a person's life path and the choices they make. I've met people who spent 30 years doing deep meditation practices and they told me that they accomplished more in one LSD or ayahuasca trip than they did in all those years. I've also met people who were ruined by excessive psychedelic use; they seem caught in that third eye play land and they have a lot of trouble relating to their earthly, human level self.
I guess I can really only reflect on my own experience. I was 100% compelled to seek out psychedelics and my life led me to people who had very pure amounts on hand. These people were also trained psychologists and psychotherapists. It was just in the cards for me. The cycle of psychedelic bungie jumping ran its course with me. After a couple of years I outgrew it and now I do them rarely. The main reason they don't hold interest is because they show you the divine and then you have to come down again. It creates a false sense of separation. They show you what is possible though, perhaps, and give you something to strive for. Now I am going about the business of opening myself in more grounded, organic ways... forming pathways one at a time in unique structures that are necessary to my personal path, instead of having every pathway blown open simultaneously whether I want it to be or not.
My life is heading from that intense, shamanic death/rebirth "it has to be hard" place to simplicity and embodiment, and for me personally psychedelics are not conducive to that. Having to come down into myself after years of psych use has been challenging, but rewarding. All that esoteric, divine wisdom is now being put to use in a way where I get to differentiate myself as "me", in a separate body, something I very much need at this point in my life. I've learned to seek neuroplasticity and novelty in other gentle ways that don't require me to blast myself open, but I don't think I could've got to this point without some of the foundations psychedelics brought me.
I think the cautions of some gurus about "drug use" stem from the illusions and false unities they create, which keep people chasing that feeling through a substance, rather than establish those pathways within themselves in another way. (This is the way it has been put to me.) At the same time, a lot of those pathways were established for me by psychs. Most people approach life from the ground and move up... like they get a job, get married, have a family, do all the mundane material stuff, and then later in life they start going into deeper spiritual questions. Some people. For me it has been the opposite. I went far out and far in, and now I am returning to all those simple worldly things. Like, why bother pondering the nature of the universe when there is already so much in this moment, maybe I'll just go sit under that tree and eat lunch while watching the birds, that kind of thing. That seems to be the order of operations in my world, from what I can tell.
But... the people who I used to do psychs with? They are still doing them and enjoy them regularly. Some people are on that track. I may do psychs again so who knows, but for now at this point in my life they are irrelevant.
As with all things, follow the wisdom of your heart. The guru within knows better than the outer guru. I met gurus in India and Nepal who have done psychedelics. It's not cut and dry no matter what any one single person has to say about it. And there is no right or wrong. The gurus are giving advice from a compassionate place based on their understanding of reality... they truly are trying to be helpful, but it's up to you to turn inward and see what your own spirit is telling you about your truth of the matter.