I’m surprised so many are saying they wouldn’t have done that even before COVID as for some kids it can be a fun trip.
I don't think anyone has said they'd never take their dc to a supermarket. People are saying it's not something we would choose to do 'as a whole family' and certainly not, as the title of this thread suggests, " going out as a family". Loads of us have had to take the dc out of necessity of course, and I'm sure lots of us have taken one child out of the family for some 1:1 time away from siblings (before Covid), to be 'the helper' that day.
Oh and late teens early twenties buying trolly fulls of food and alcohol like there some party going on.
eh? Some leap of imaginagtion there. My adult dc buy food - er - because they need to eat for the week, same reason I buy food 
Yes, I've no doubt alcohol is involved, as they can't go out to meet friends in pubs and clubs like everyone else did at that age, so they either have a drink with their flatmates / house sharers or raise a glass on zoom socials, just as many adults are doing.
Indeed, in the Summer, my young adult ds was doing the family shop for us each week, as he was on furlough and we were both still working. Is that kind of thing banned now in your world ?