People can't drink for shit anymore
You meet your friend's new partner, you offer them a good wine at the end of the evening and you're looking forward for the conversation to loosen to up a bit after initial formality.
Scenario 1: "oh no thanks, I quit drinking 2 years ago, just had to do it for my health you know, but you go ahead". You dig a little deeper and out turns out they never had more than 3 drinks on a night out, but they describe that period of their life as "dark" and "out of control".
Scenario 2: They accept your offer but get hysterically drunk after 2 glasses and are now making lurid jokes and are ranting about 4 year old hot button topics.
Knowing how to drink is a skill. Learning your limit, building up enough of a tolerance that you can keep up with normal people, and of course, not becoming an alcoholic. It used to be a skill most people picked up inadvertantly and unfortunately it's becoming increasingly rare.