I remember my father and his colleagues used to have drinks together on occasions, and throw up, and get home sick, and wake up with a headache. My father hated alcohol, yet he still felt obliged to drink together. I had acquainted several of his colleagues, and not surprisingly, none of them like drinking. Most of them hated drinking.
So, it's actually a self-fulfilling prophecy. Everyone thought others expected everyone to drink, thus showed up to drink, and validated everyone's expectation.
If they were to sit down, sober, honest about their not liking alcohol, they would have found that a bunch of people who didn't enjoy drinking, forced themselves to drink with one another.
This impression was marked on my mind, that I initially thought I always had to drink, too.
But, I was wrong; we had plenty to do in gatherings, BBQ-ing, playing cards and board games. And as long as I'm into some of the activities, not drinking isn't a barrier to friendship, or trust, or "team spirit".
It's quite liberating that the circle I'm in has jumped out of the self-fulfilling prophecy of "obliged to drink".