It used to be, 100 or 200 years ago, that your workplace, your home, and your usual hang-out place were all within reasonable walking distance of each other. It wasn't a huge deal to go out and meet new people, as you'd naturally bump into them every day.
Nowadays we have a large portion of people in bedroom communities, isolated in a sea of houses. They drive in isolated cars to their workplaces, swing by to get some Starbucks on the way in, and that's the extent of their social interaction. Apart from libraries and parks, there's not many places that you can regularly go and just "hang out" without spending money just to exist in that space. It's incredibly easy to go for weeks or months without any substantial social contact outside of work or your few neighbors.
I feel like this is a reason why internet organizations and social media have exploded in popularity, for that matter. It's the new "default place" to hang out and get social interaction, for better or for worse.
(I expanded on this in an article I wrote, https://invisibleup.com/articles/31/, if you want to check that out.)