And I think it's always been like that. I could never just hang out with people for no good reason. It's easier when we share a common interest. As a consequence, I also never know what to do on family days with the in-laws. (My family is easy; we're all nerds.)
There's a lot of binary thinking in this thread.
First of all the article is weirdly misleading where the cheezy intro picture (cheezy as in giant intro pix are so 2011 and its not 2011 anymore, although the stock photo itself is a bit cheezey) is mom with a "Waltons"-full or "Bradys"-full herd of her own small children, but the article clearly states she has no kids and is waiting for her biological clock to ring off the hook or something. Maybe this "I'm bored" is mother natures evolutionary way of subconsciously motivating women to start squirting out kids. One thing that is unarguable is the editor who picked out the intro pix didn't bother even skimming the article.
When my kids were infants and toddlers I had a pretty good excuse to burn a ridiculous amount of time on IRC and discussion groups and multiplayer games, which were kinda the social media of their day. But that only lasts a couple years and now I socialize more than when I was single!
Kids often participate in scouts, church, after school clubs (Vex Robotics, etc) and especially sports. Theoretically at least a small part of the rationalization for making (forcing?) kids to do that stuff is to teach kids how to make friends and socialize, but it hardly stops at 18... There's two couples specifically we hang out with constantly during soccer season because our kids play, and another couple hangs out with us at every basketball practice and everyone hangs out together and basically tailgates at baseball. My wife became friends with a mom at a "kids learn how to cook" class and they're always talking and my wife got her friend's daughter a job where she works etc etc etc. My daughter is on a bowling team and has made a friend on the team and no my wife hangs out with her mom quite a bit.
There's a lot of fake sounding rationalization about parents "forcing" their kids into activities and I think a much more practical realistic explanation is the parents don't really care if their kid is making lego robots or baking cookies or playing sportball, the parents just want a couple hours a week to gossip and eat junk food and maybe tailgate or maybe everyone goes to the restaurant afterwards, or just hang out and watch the game together or whatever.
And with respect to the increase in kids programmed activities and decrease in kids ages, no 2 year old ever asked their mom for ballet class or toddler yoga or WTF, but plenty of moms and dads of 2 years olds want to hang out with other parents. The purpose of ballet class and modern dance class is for the moms to hang out, and likewise cub scouts is basically the dads want to hang out together, oh and in both cases the kids do something to stay mostly safe and out of trouble as a secondary thing.
I'm happily married longer than I have kids so this doesn't directly matter to me, but I've observed that some of the local single moms think the sole purpose of scouting is to provide a meat market of single men for them, oh and the kids learn to tie knots or something to stay out of the way. If people have nothing else to gossip about, they'll start on that topic...