As a teetotaller, I'd say that the tipping point is usually around the third drink. I don't know about US drinking culture, but here in the UK that really isn't a lot. Beyond that point, people rapidly lose the ability to have a conversation and slide into a kind of output-only mode. There's a certain charm to that kind of free association, but as a sober person you're more of an audience member than a participant. I think anyone who works in hospitality can vouch for the fact that most drinkers become obviously cognitively impaired much sooner than they realise.
Stoned people might be lethargic and dull, but at least they're more reliably amiable than drunk people. Some people start becoming nasty after only a couple drinks - no fists being thrown, just casually cruel things that they'd never dream of saying while sober, trivial disagreements escalated into petty and personal shouting matches. You don't have to be particularly intoxicated to start saying things that your sober self would be utterly ashamed of; your saving grace is the fact that most of the people around you aren't really parsing or retaining what you're saying.
I relate to this experience (not teetotaler but slow starter/drinker and I watch my consumption).
I especially relate to the petty/cruel observations, particularly in the context of big family meals/events.
I think it's one of the reason people "like" alcohol, it gives them both the courage and an excuse to say whatever they want/feel.
But you seem to be making excuses/explanation for this, I don't agree, what people become under the influence of alcohol is who they truly are, without the mask and restraints.
If someone becomes petty/cruel/violent or whatever, you just learned that they cannot be trusted and are a bad person, no needs to explain away with alcohol influence.
In general, drugs amplify or make obvious who peoples are, they don't radically change them contrary to what some like to pretend.
Is that really true? I observe that certain drugs impact all personalities in similar ways, like cocaine making people paranoid. If you have homeless near you like most California, you spot opioid or meth drug behaviors instantly because they’re quite distinct. Alcohol does impair judgement, which predictably means less self monitoring and that may explain what you’ve noticed, that jerks get jerkier while nice guys may just get nicer on alcohol.
They key word was "radically".
Of course, every drug has a typical and general impact on how people behave and you can even notice it in physical movement (everybody expects any drunk person to have pretty bad motor control).
But this is just making my point even more, you need to observe the differences between individual behaviors under the influence, not just the difference between their behavior sober and under influence.
A drug will amplify certain key aspects of cognition/movement in the same way for everyone, someone who displays extreme specific behavior is just more noticeable because the amplification makes it very obvious, but it was always there in the first place.
I have never heard about cocaine making people paranoid but it is just something that every drug user displays at some point (because of the fear of being found out, judged and maybe having trouble with the police).
Even though I am an extremely chill person, I have found myself to be a bit paranoid under the influence of cannabis at times.
And I have a question for you: is it the drug that makes people paranoid or is it that people who are inclined to paranoid behavior are more likely to use drugs, which amplify the behavior.
People regularly using drugs have issues that push them to this abuse, it's not really the drug that are the problem, the root of the issue is really in the people and their personnality/character.
Stoned people might be lethargic and dull, but at least they're more reliably amiable than drunk people. Some people start becoming nasty after only a couple drinks - no fists being thrown, just casually cruel things that they'd never dream of saying while sober, trivial disagreements escalated into petty and personal shouting matches. You don't have to be particularly intoxicated to start saying things that your sober self would be utterly ashamed of; your saving grace is the fact that most of the people around you aren't really parsing or retaining what you're saying.