Our experience of consciousness is entirely our own. If we don’t vary it against a constant background, how do we know what sobriety even is?
Put another way: is the “sober” view of a person with schizophrenic hallucinations truer than that after they’ve taken an antipsychotic?
But I'm not sure that's useful for answering the question of why we exist, why the universe exists.
I’m not advocating for or against the use of mind-altering substances. But a scientist with two microscopes is going to have an edge over one who dogmatically subscribes to their one and only favourite. Even something as simple as observing the sky turns on knowledge of the failure of our neuro-optical pathways qua optical illusions.
If you are looking for an answer that makes sense in relation to your specific context, your life, your consciousness, then drugs might be useful.