OP asked 'Is drinking going out of fashion?'
I wonder if there are generational peaks - teen - early adult years and possibly later adult years. Somewhere in the middle, when children arrive, perhaps people cut back a little. And as the OP says, if people are on regular medication, this may give cause to cut back too.
When my DD was pregnant she didn't drink at all, but alluded to looking forward so much to a glass or two once the baby had arrived. I could tell I gave her pause for thought when I. said 'Well one parent always needs to be sober in years to come, in case of emergencies...' I can see, from the unopened gifted bottles that are lining up, that she and SIL have cut back considerably.
When I was young, (born 1963!) we simply didn't drink like young people do now. In my 20s / 30s, we had alcohol at Christmas and Easter and not in between unless we had a dinner party. Now we have a wine rack stacked with bottles and more chilling in the fridge and this is the norm. We enjoy a bottle or 2 over the weekend as a regular thing - don't drink at all during the working week. I think my retired parents-in-law have a tipple of something everyday. My guilty pleasure at the moment, as I am still on holiday, is having a glass of the left over Easter port every evening - hits a spot, but when it's gone, it's gone and I won't have another bottle until Christmas!