I grew up before the internet and I never learned how to navigate parties. I think it depends more on being able to see somebody close to you to learn from.
EDIT: I do have a different expectation for parties, but understand that parties have a spectrum, from people going to a party to drink/smoke/bump what have you to reach a point of near senselessness on one end of the spectrum, to perhaps a gathering of people in the same industry who are trying to "network" at the other. My expectation for informal parties is in the middle of this where people may drink but where it isn't their expectation that they will get drunk, and the discussions will be more intimate and not business related.
You also have the problem that people get suspicious of people hanging around not drinking alcohol.
It sounds like they wanted a hobby meetup group or similar.
Once you're out of college I think this is mostly in your imagination. Nobody will judge you for drinking water or diet soda and you similarly shouldn't judge someone for enjoying a beer at a social event.
The actual alcoholics drink alone. (And that's essentially the problem.)
Some would say it's sad that we can't just gather around a table just to talk. But the advantage of the drink (not necessarily alcoholic), is you have to be there and not on the phone.
Compare it to other “drug cultures”, e.g. cocaine. Of course users socialize heavily, but that does not mean that they are not addicted or harming themselves.
The only major thing that seems to have changed are the names of the distractions.
this is a true statement, but idk how different it really is for the kids. when i was a kid i would happily spend hours rereading the same garbage star wars expanded universe books over and over and over, even though i had basically memorized the plot. with the abundance of content, i doubt today's children would be as satisfied to revisit the same thing so many times, but i also doubt that they waste much more time than i did.
My point is that the nature of what kids do at parties hasn't changed in any significant way to support your original claim that there are "so many basic things we just don't learn how to do anymore".