My parents lived in the same town for most of their lives, as did the majority of their friends, so they had a large circle of friends that they'd known since they were young. It was quite easy to hold a dinner party with so many people nearby who all knew each other well and everybody would drink and drive home afterwards, so no need to arrange designated drivers or go to the trouble and expense of booking a taxi.
DH and I live far away from where we grew up. Our long-standing friends from school, uni etc are scattered (many of them don't even live in the same country as us), so seeing them involves lengthy travel, overnight stays etc. We do have local friends that we have made at our DC's school etc but they're much newer friends and I guess it's more awkward to make that first step and try to match compatible people together for social occasions.
Also, my mum was part of a "babysitting circle" when I was little, so a succession of unknown (to my mum) babysitters would turn up to look after us when my parents went out. No money changed hands - it was all done on credits, so if you had babysat for four hours, you had earned four hours of babysitting from the circle.
I tried to set up a baby-sitting circle when my DC were small, but the people I invited to join it were (understandably, nowadays) horrified at the idea that a stranger might turn up to look after their kids. I realised I wasn't comfortable with the idea either - I'd just asked people I knew and liked, but if the circle expanded and my friends asked their friends, then I wouldn't know everyone. We ended up using an agency, where every babysitter was DBS checked and paediatric first aid trained, and we could select by the age, sex or occupation (eg nursery nurse) of the babysitter. But it was very expensive - often more expensive than the cost of our restaurant meal/theatre tickets etc, so we didn't do it very often.