There are other hobbies and gathering places that don't revolve around consuming carcinogens such as restaurants, gyms, sports leagues, libraries, ice cream shops, opium dens (although I'm not sure how many exist nowadays) and likely more that I can't think of. Not to mention, there are many beverages that don't contain alcohol.
"That was a fun day of work, let's hit the library" is not the same as "Let's go have a beer," for many people, as you're probably aware :-) To each their own, though. Your argument is just that people should stop doing what they enjoy - again, I think most understand a potential risk, they've just decided it's worth it.
Well nonalcoholic beer does exist, but I assume you aren't talking about that.
I personally find libraries incredibly relaxing, but I assume what you mean by "it's not the same" in that a library doesn't serve highly rewarding GABAergic drugs.
People enjoy drinking alcohol because it is rewarding and most have learned to like the taste through the association of that neurological reward. That's generally what enjoyment is, association of reward with an activity. There are many other activities and compounds that are just as rewarding or relaxing but society is conditioned to accept alcohol as the default it seems, at least in some communities.
As for your last point, that is absolutely not true from my experience. Whenever I discuss the risk of cancer that's associated with alcohol consumption the other person generally has no idea, that has been over 90% of my conversations on the topic.
