When I was younger though (and child free), I'd jump at these sort of events, and loved them. A company I used to work for wrapped up about 6pm, except Friday when you were still expected to be around until 6, but there were beers and soft drinks plus snacks from 5pm. Most people would still end up talking work, and plenty of us would still be there talking work (in various guises) until 7pm or later, and would carry on to the pub to do the same if we fancied it. But I loved the fact it started in 'working hours' and that the snr staff would all get involved. Was a great icebreaker and helped move silos between teams and departments.
Now I'm older, if it is outside of working hours, I have to see the benefit in it for me.