yes, you can buy a single glass of wine at many bars and restaurants. while somewhat triggering to the oenophiles, you can also buy wine packaged in 12 oz cans, which is close to a standard pour if split between two people.

I get that this was probably a tongue-in-cheek question, but like many other things, drinking follows a power law distribution. there are many more moderate drinkers than heavy ones.

I usually have a glass of wine with dinner :) . I have an actual chalk mark on a measured standard "glass" lol. I do not have more than that. Sometimes I'll have a beer instead if it's fish and chips. I don't drink more than that, except maybe on the weekend during a social "thing". Those aren't very often though, mostly once a month.