I used to drop acid and take shrooms in my teens and 20s. I also drank a lot, smoked a lot of pot, did as much coke as I could and by the time my world finally caved in on me, I was smoking crank (methamphetamine) from my mid 30s to when I finally got sober for good more than 20 years ago in 2004 at 41. At some point in these past 20+ years, this idea of "microdosing" became a thing.
I have no idea how much a microdose is. I do know that different types of mushrooms got me higher than others and, usually, the more I took in a particular "dose" the higher I got. And, if I didn't take enough, not much happened. The same can be said of LSD. But, if we are talking about "spiritual" experiences, being "enlightened," and the like - I have had profoundly enlightening experiences, sometimes, with just particularly good marijuana.
But - and this is a big but - I would not risk my sobriety by altering my consciousness artificially again after all these years mind-chemical free (and, to be clear, psilocybin, lysergic diethylamide acid and mescaline are all psychoactive chemicals). I do not discount that there might be legitimate medical applications for such drugs - and others - but it's the wild, wild west and there are a lot of people who think they know something, and don't. There are far too many snake oil peddlers out there taking sober people right back into addiction.
Your last paragraph does serve as a disclaimer, granting that just eating some shrooms in moderation, absent anything else, will cure our pesky little alcohol problem. I applaud that, this is the exception rather than the rule among those on the "microdose" bandwagon. Because without a comprehensive treatment plan, any therapy that just introduces one drug to stop another is no different than when I used crank to solve my crack problem. Which, by the way, worked.