100% this. Started out with two families buying houses near each other in a family centric LA neighborhood (Eagle Rock). Then it expanded to 3 --> 4 --> 5 all within walking distance. We all have similar aged children. It's magic. We watch each others kids, do frequent backyard/park/sleepover playdates, and help w dropoff/pickup. It makes parenting SO MUCH EASIER. I often joke that I'm not a real parent bc we have so much help. Living closer meant compromising on other decisions (ideal house/commute/etc), but proximity to friends has more than outweighed the cons. One family was living near the beach and loved it, but decided it was more impt to live near us then right on the coast.

We opt in and out as much as we'd like. It's beautiful having options, mostly for our kids, who are really thriving by having easy access to playmates. So much better than having to "blind date" other couples and their kids from daycare/activities/etc.

The hardest part is starting. It doesn't have to be a huge commune initiative. Pick one friend who has a similar lifestyle and settle down in a neighborhood withing walking distance and take it from there. Think most important time to do it is when you become a new parent, when your kids and you will want companionship but won't have the time (nor energy) to build new relationships.