You pointed out one aspect: the in inconsistent concentration of intoxicants. You are missing another crucial point: time until onset of the effects. It is mu

You pointed out one aspect: the in inconsistent concentration of intoxicants. You are missing another crucial point: time until onset of the effects. It is much easier to consume a lethal dose of mushrooms than ethanol before your body violently rejects the poison (colloquially known as "vomiting")